Estimate each product 11.9×21=

Answer:

a b d e

Step-by-step explanation:

i just took the test and got a hundred

Equations A, B, and E are true, i.e 66: 10 = 6.6, 660: 10° = 66, 6: 100 = 0.06​.

An equation is a statement that two expressions, which include variables and/or numbers, are equal. In essence, equations are questions, and efforts to systematically find solutions to these questions have been the driving forces behind the creation of mathematics.

Make sure your equation is correct by comparing the values on either side of the equals sign to create a true equation. A true equation must have the same numerical values on both sides of the "=" sign. One real equation is, for instance, 9 = 9. A valid equation is 5 + 4 = 9.

As a result, the true equations are,

66: 10 = 6.6

660: 10° = 66

6: 100 = 0.06​

Thus, equations A, B, and E are true, i.e 66: 10 = 6.6, 660: 10° = 66, 6: 100 = 0.06​.

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Answer:

the answer is 12.2

[tex] \frac{b}{0.52} \\ we \: know \: b = 6.344 \\ then \\ \frac{6.344}{0.52} \\ = 12.2[/tex]

Answer:

The solution to a system of linear equations is the ordered pair (or pairs) that satisfies all equations in the system.  The solution is the ordered pair(s) common to all lines in the system when the lines are graphed.

Lines that cross at a point (or points) are defined as a consistent system of equations. The place(s) where they cross are the solution(s) to the system.

Parallel lines do not cross. They have the same slope and different y-intercepts. They are an example of an inconsistent system of equations. An inconsistent system of equations has no solution.

Two equations that actually are the same line have an infinite number of solutions. This is an example of a dependent system of equations.

Step-by-step explanation:

Solve the system of equations graphically.

3x + 2y = 4

−x + 3y = −5

Solution

Graph each line and determine where they cross.

The lines intersect once at (2, −1).

A graphic solution to a system of equations is only as accurate as the scale of the paper or precision of the lines. At times the point of intersection will need to be estimated on the graph. When an exact solution is necessary, the system should be solved algebraically, either by substitution or by elimination.

Substitution Method

To solve a system of equations by substitution, solve one of the equations for a variable, for example x. Then replace that variable in the other equation with the terms you deemed equal and solve for the other variable, y. The solution to the system of equations is always an ordered pair.

Example

Solve the following system of equations by substitution.

x + 3y = 18

2x + y = 11

Solution

Solve for a variable in either equation. (If possible, choose a variable that does not have a coefficient to avoid working with fractions.)

In this case, it's easiest to rewrite the first equation by solving for x.

x + 3y = 18

x = −3y + 18

Next, substitute (−3y + 18) in for x into the other equation. Solve for y.

2(  3y + 12x + y = 11

2(−3y + 18) + y = 11-------Substitute -3y + 18 in for

   −6y + 36 + y = 11-------Distribute.

2(3y −5y + 36 = 11-------Combine like terms.

2(3y +  18−5y = −25-----Subtract 36 from both sides

2(3y + 18) +  y = 5----   -Divide both sides by -5.

Then, substitute y = 5 into your rewritten equation to find x.

x = −3y + 18

x = −3(5) + 18

x = −15 + 18

x = 3

Identify the solution.   A check using x = 3 and y = 5 in both equations will show that the solution is the ordered pair (3, 5).

Elimination Method

Another way to solve a system of equations is by using the elimination method.  The aim of using the elimination method is to have one variable cancel out. The resulting sum will contain a single variable that can then be identified. Once one variable is found, it can be substituted into either of the original equations to find the other variable.

Example

Find the solution to the system of equations by using the elimination method.

x − 2y = 9

3x + 2y = 11

Solution

Add the equations.

 x −  2y = 9

3x +  2y = 11

4x +  2y = 20

Isolate the variable in the new equation

4x = 20

 x = 5

Substitute x = 5 into either of the original equations to find y.

 x − 2y = 9

(5) − 2y = 9

     −2y = 4

        y = −2

Identify the ordered pair that is the solution.   A check in both equations will show that (5, −2) is a solution.

It may be necessary to multiply one or both of the equations in the system by a constant in order to obtain a variable that can be eliminated by addition. For example, consider the system of equations below:

3x + 2y = 6

 x − 5y = 8

Both sides of the second equation above could be multiplied by −3. Multiplying the equation by the same number on both sides does not change the value of the equation. It will result in an equation whereby the x values can be eliminated through addition.

Special Cases

In some circumstances, both variables will drop out when adding the equations. If the resulting expression is not true, then the system is inconsistent and has no solution.

4x + 6y = 13

6x + 9y = 17

3(4x + 6y = 13)

2(6x + 9y = 17)

12x + 18y = 39

12x + 18y = 34

             0 = 5

The equation is false.  The system has no solution.

If both variables drop out and the resulting expression is true, then the system is dependent and has infinite solutions.

6x + 15y = 24

4x + 10y = 16

2(6x + 15y = 24)

3(4x + 10y = 16)

12x + 30y = 48

12x + 30y = 48

             0 = 0

The equation is true.  The system has an infinite number of solutions.  (Notice that both of the original equations reduce to 2x + 5y = 8.  All solutions to the system lie on this line.)

Answer:

c

Step-by-step explanation:

In Line 4, she forgot to take the negative square root, because squaring both 8 and −8 equals 64.

Answer:

9a + 3b + 6c

Step-by-step explanation:

4a-6b+9c + 5a+9b-3c

4a + (-6b) + 9c + 5a + 9b + (-3c)

(4a + 5a) + (-6b+9b) + (9c-3c)

9a + 3b + 6c

Answer:

the person below is correct I believe

Step-by-step explanation:

hope this helped have a good rest of your night :)❤

Answer:

42x-42

Step-by-step explanation:

(7x)(6x)+(6)(-7)=42x°-42°

Answer:

Answer is A

Step-by-step explanation:

Subtract 47 from both sides to get 0

3x² - 18x - 42 = 0

Use Quadratic formula to get

[tex]3+\sqrt{23} \\3-\sqrt{23}[/tex]

Answer:

Step-by-step explanation:

Answer:

A. He can decrease the simple spacw

Answer:

D. He can increase the number of trials

Answer:

8

Step-by-step explanation:

Answer:

8

Step-by-step explanation:

5 + 3 = 8

-Lexi

Answer:

5

Step-by-step explanation:

The answer is 60/12 becuase we can simfly both of theese mixed numbers into an improper fraction, wich will be 4/3*15/4. We do the multiplication, and we get 60/12. 60/12 can be simplifed to 5 becuase 60 divided by 12 is 5

Step-by-step explanation:

It is represented by ,

=> y ≥ 1/4x -1

Since you have the answers, I'll just show the steps on how to get there.

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Problem 19

[tex](1+4i)^2\\\\(1+4i)(1+4i)\\\\1*1 + 1*4i + 4i*1 + 4i*4i\\\\1 + 4i + 4i + 16i^2\\\\1 + 4i + 4i + 16(-1)\\\\1 + 4i + 4i-16\\\\(1-16) + (4i+4i)\\\\(1-16) + (4+4)i\\\\-15 + 8i\\\\[/tex]

Keep in mind that [tex]i = \sqrt{-1}[/tex] by definition. Squaring both sides leads to [tex]i^2 = -1[/tex]

In the second step, I used the idea that x^2 = x*x. Right after that, I used the FOIL rule to expand everything out.

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Problem 21

We could follow the same idea as problem 19, but I'll use a different approach.

[tex](A+B)^2 = A^2+2AB+B^2\\\\(3+i)^2 = 3^2 + 2*3*i + i^2\\\\(3+i)^2 = 9 + 6i - 1\\\\(3+i)^2 = 8 + 6i\\\\[/tex]

The formula on the first line is the perfect square binomial formula.

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Problem 23

The FOIL rule can be used if you want, but I'll use the difference of squares rule instead.

[tex](m+n)(m-n) = m^2 - n^2\\\\(3+5i)(3-5i) = (3)^2 - (5i)^2\\\\(3+5i)(3-5i) = 9 - 25i^2\\\\(3+5i)(3-5i) = 9 - 25(-1)\\\\(3+5i)(3-5i) = 9 + 25\\\\(3+5i)(3-5i) = 34\\\\[/tex]

It turns out that multiplying any complex number of the form a+bi with its conjugate a-bi will result in a purely real number (that has no imaginary part). More specifically: [tex](a+bi)(a-bi) = a^2+b^2[/tex]

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Problem 25

We could use the difference of squares rule again, but I'll show a different approach. This time using the distribution rule. The FOIL rule could also be used if you wanted.

[tex](6+7i)(6-7i)\\\\x(6-7i)\\\\6x-7xi\\\\6(x)-7i(x)\\\\6(6+7i)-7i(6+7i)\\\\6(6)+6(7i)-7i(6)-7i(7i)\\\\36+42i-42i-49i^2\\\\36-49(-1)\\\\36+49\\\\85\\\\[/tex]

I used x = 6+7i and the substitution property to help distribute. Lines 3 and 6 are where distribution is applied.

Recall the half-angle identity for cosine:

cos²(x) = 1/2 (1 + cos(2x))

Then we can rewrite the integrand as

cos³(4x) = cos(4x) cos²(4x) = 1/2 cos(4x) (1 + cos(8x))

So we have

[tex]\displaystyle \int \cos^3(4x) \, dx = \frac12 \int (\cos(4x) + \cos(4x)\cos(8x)) \, dx[/tex]

Next, recall the cosine product identity,

cos(a) cos(b) = 1/2 (cos(a - b) + cos(a + b))

so that the integral is equivalent to

[tex]\displaystyle \int \cos^3(4x) \, dx = \frac12 \int \cos(4x) \, dx + \frac14 \int (\cos(4x - 8x) + \cos(4x + 8x)) \, dx[/tex]

[tex]\displaystyle \int \cos^3(4x) \, dx = \frac34 \int \cos(4x) \, dx + \frac14 \int \cos(12x) \, dx[/tex]

Computing the rest is trivial:

[tex]\displaystyle \int \cos^3(4x) \, dx = \boxed{\frac3{16} \sin(4x) + \frac1{48} \sin(4x) + C}[/tex]

Answer:

Sometimes it's better to leave them as roots because it's easier sometimes to solve problems with them still as roots

Answer:

We choose to leave radicals as roots without calculating them because calculating the square roots of a non perfect squares result in an irrational, non terminating decimal.

Step-by-step explanation:

Why do we do Radicals in the first place?

Radicals are used to write the square root or the nth root of a number. We sometimes leave specific numbers (non-perfect squares) as a radical because the output would be infinity

Example:

[tex]\sqrt45[/tex] is not a perfect square, it lies between [tex]\sqrt36[/tex]  and [tex]\sqrt49[/tex]

This means the number lies in between 6 and 7

The true root of 45 is irrational. Recall that irrational numbers are numbers of non-perfect squares. [tex]\sqrt45[/tex] = 6.7082039.......

Simplify:

[tex]\sqrt 45 = \sqrt 9 * \sqrt 5\\[/tex]

[tex]= \sqrt3^2 * \sqrt 5\\\\ \\= 3\sqrt5[/tex]

We choose not to pursue simplifying this because  [tex]\sqrt5[/tex]  is irrational (square root of a non-perfect square)

Summary:

We choose to leave radicals as roots without calculating them because calculating the square roots of a non perfect squares result in an irrational, non terminating decimal.

-Chetan K

Answer:

the ansewer is 56

Step-by-step explanation:

Answer:

$425000

Step-by-step explanation:

561000*100/132=425000

60

Step-by-step explanation:

(-47)-(-107)

(-47)-1(-107)

-47+107

=60

Answer:

w = win

Step-by-step explanation:

w=13

Answer:

w = 13

Step-by-step explanation:

16w - w = 15w

15w - 12w = 3w

3w - 2w = w

w = 13

Answer:

After reviewing the question you posted I have deduced that the correct answers are:

11) Max has $10.00. He earns $25.75 per lawn that he mows.

12) No. She is wrong. She did not group like terms correctly.

Step-by-step explanation:

11)

For 11) I first identified the independent variable of the equation, being "10".

And then the dependent variable of the equation, being "25.75". (The dependent variable of an equation will always be affected by the x)

I then looked at all the possible answers to see which one shared a independent variable of "10" and a dependent variable of "25.75".

The only possible answer that matches is Max has $10.00. He earns $25.75 per lawn that he mows.

This is because the only two possible answers that have "10" being a variable that does not change (independent variable) are:

--- "Max has $10.00. He earns $25.75 per lawn that he mows.

--- "Jon buys 10 toycars for $25.75 each"

However!

"Jon buys 10 toycars for $25.75 each" is an incorrect answer because it uses "10", although independent, as the x variable that affects the independent variable of "25.75".

12)

To find the correct answer for this question I simplified the equation from:

8t-15+3t   =   11m-15

Into:

8t+3t-15   =   11m-15

Which further simplifies into:

11t-15   =   11m-15

Which then you can notice that the two equations are similiar indeed, however they do not share like terms. One equation has "t" as their term, and the other as "m" as their term. Thus they do not share any like terms and are not equivalent.

Answer:

b = 24 ft

h = 10 ft

Step-by-step explanation:

120 = ½hb

120 = ½h(3h - 6)

240 = h(3h - 6)

240 = 3h² - 6h

 80 = h² - 2h

    0 = h² - 2h - 80

    0 = (h - 10)(h + 8)

    h = 10 ft or -8 ft

 we ignore -8 as it makes no sense for a triangle side length.

b = 3(10) - 6 = 24 ft

Answer:

Can you provide how long it took to print per copy

Step-by-step explanation:

Answer:

it will take him 50 min because their are 730 and that is lot so it will take him 50min

Answer:

$154.96

Step-by-step explanation:

difference means to subtract so 879.95-724.99=154.96

Answer:

y = 10

Step-by-step explanation:

y = (-2)(x) + 4

y = (-2)(-3) + 4

y = 6 + 4

y = 10

Answer:

The ribbon costs 1.25 per meter

Step-by-step explanation:

5/4=1.25

Answer:

it would take 100 days for it to get better that just makes sense I think and for number two it would be 365% better

Step-by-step explanation:

Answer:

b

gnzjfzjgzjxjgzfjsngdjgsjfzgjskzjtztjsgjd5uduajai

Answer:

16

Step-by-step explanation:

8x8 is 64, so half of 8 is 4 so 4x4 is 16

9 1/2 is the same as a number decreased by 15

I guess that's the right answer maybe i'm wrong if I am oh well