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Answer:

  (x, y) = (1, 1)

Step-by-step explanation:

About Algebra

All of Algebra is based on a few simple rules:

When we solve equations by substitution, we make use of these facts.

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About Substitution

Generally, substitution in equation solving is done for the purpose of eliminating a variable from the equation. That usually means you want to write an expression for one variable in terms of other variables.

Finding the Expression to Substitute

In this set of equations, the variables are x and y. We can substitute for y an expression involving x, or we can substitute for x an expression involving y. These equations are written in such a way that either method works as well as the other.

Let's choose to substitute for y. This means we need an equation of the form ...

  y = <some expression involving x>

The first equation makes it easy to get that. If we add y (to both sides, see rule 3 above), we get ...

  5x -y +y = 4 +y

  5x = 4 + y . . . . . . . . . simplified

Subtracting 4 (from both sides) gets us the form we want.

  5x -4 = 4 -4 + y

  5x -4 = y . . . . . . by rule 4 above, we can use (5x-4) anyplace you see y

Using the Expression to Substitute

Now, we have an expression for y that we can use in the second equation. There, y is multiplied by 4, so we need to be sure to multiply the whole expression by 4:

  -x + 4(5x -4) = 3 . . . . . . substituted for y in the second equation

  -x +20x -16 = 3 . . . . . use the distributive property to eliminate parentheses

  19x -16 = 3 . . . .  . . collect terms

This has a constant (-16) where we don't want it, so we can add 16 (to both sides) to get rid of it.

  19x -16 +16 = 3 +16

  19x = 19 . . . . simplify

Now, we can divide by 19 (to both sides) to get x by itself.

  (19x)/19 = 19/19

  x = 1 . . . . almost done; we still need to find y

Finishing Up

Using the equation for y that we used for substitution, we can find y from our value of x.

  y = 5x -4 = 5×1 -4 = 5-4

  y = 1

So, the solution is x = 1, y = 1, or (x, y) = (1, 1).

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Additional comment

In this set of equations, both variables (x and y) appear with coefficients of 1 (actually, -1). This makes it easy to solve for an expression that can be substituted for the variable. In systems of equations that you want to solve by substitution, it usually works well to start by looking for a variable with a coefficient of 1 (or -1). Use that to write the substitution expression as we did here.

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Alternate Solution

If you use a variable with a coefficient other than 1 to write the substitution expression, you end up with fractions. That's OK if you're comfortable with arithmetic using fractions. It generally requires more care.

For example, we could solve the first equation for x:

  x = (4 +y)/5

Substituting that into the second equation gives ...

  -(4 +y)/5 +4y = 3

  -4/5 -y/5 +4y = 3

  (3 4/5)y = 3 4/5 . . . . . add 4/5 (to both sides), collect terms

Now, you get to divide by 3 4/5 to get ...

  y = (3 4/5)/(3 4/5) = 1

Fortunately, in this case, we can see the numerator and denominator are identical, so the division result is 1. If it weren't you'd be faced with dividing mixed numbers--not always a student's first choice of fun math operations.

  x = (4 +1)/5 = 1 . . . . finishing up

Answer:4

Step-by-step

Answer:

225 I just checked tell me if you're right

Answer:

15*15 = 225

15*15 is the same as [tex]15^{2}[/tex]

if you wanted to sit there you could add 15 with itself 15 times and you'd get 225.

no matter how ya do it, 15 *15 is 225

Step-by-step explanation:

Answer:

18 racers finished.

Step-by-step explanation:

In the first half, 30 racers dropped out, because 2/3 of 45 is 30. In the 2nd half, 12 racers dropped out, because that is 2/5 of 30. So, in the end, 18 racers finished. (I might have done this wrong i did my best)

Answer:

11 is natural, real, integer and whole number.

1% is irrational and real, integer.

√25 = 5 hence it's natural, real, integer and whole

√50 is rational and real, integer.

1.333… is natural, real and integer

2.3×10^5 is natural, real, integer and whole number.

Answer:

3x-6+1

Step-by-step explanation:

I know algebraaaaaa

Answer:

the original volume is 4.0L

Step-by-step explanation:

Step one:

given data

V1= ?

T1=  52 °C

V2= 6.1L

T2=  79° C

Step two

applying the volume temperature relationship, which is

V1/T1= V2/T2

substituting we have

V1/52= 6.1/79

cross multiply we have

52*6.1= V1*79

317.2= 79V1

divide both sides by 79

V1= 317.2/79

V1=4.0L

1a. closest to 1

b. closest to 0

2a. closest to 1

b. closest to 1/2

Numb 3. Ain't clear.

4. Not sure.

5a. closer to 1

b.closer to 1/2

c. 3/4 - 5/12 = 1/3

6. 26/15

7. 7/18

8. 47/240

9. 191/225

10. 11/60

11. 81/200

Answer:

19

Step-by-step explanation:

Answer:

60

Step-by-step explanation:

first you have to find 50% of 40 but multiplying 40 by .5 to get 20. then you add 20 to 40 to get your answer

Answer:

60!

Step-by-step explanation:

100% is 40

to increase that by 50, do 1.5 times 40

the answer to that is 60

Answer:d) g(x)=x^1/3-1.5

Step-by-step explanation:

Answer:

Irrational numbers cannot be written as a fraction, or the ratio of two whole numbers.

You would have to find a GCF (greatest common factor) and multiply it out of the radical.

ex.

[tex]\sqrt{6}[/tex] = 2 x 2 x 2

when you have to multiplier numbers then you can combine two of them to take outside the radical, meaning 2x2x2

2[tex]\sqrt{2\\}[/tex]

so [tex]\sqrt{6}[/tex] would be closest to the positive 2 on the number line and 2 notches.

[tex]\sqrt{11}[/tex]

is an irrational number, so it might fall into 3.3 if turned into a decimal.

Step-by-step explanation:

Answer:

i is probably 1.

Step-by-step explanation:

1^3 is equal to 1

1^47 is equal to 1

Answer:

b

Step-by-step explanation:

Answer:

2t-g

Step-by-step explanation:

Collect like terms

3t-t= 2t

2g-3g= -g

2t-g

Answer:

Y=-1+2x/3

Step-by-step explanation:

Move all the terms that don't contain y to the right side and solve. Hope this helps!

Answer:

Write a situation in which positive and negative numbers are used to describe values that have opposite meaning. What does 0 represent in this situation you created?

Step-by-step explanation:

Answer:

-4/3

Step-by-step explanation:

2^(8x-8)=4^7x

2^8x-8=4^7x

2^8x-8=4^2×7x

8x-8=2×7x

8x-8=14x

-8=14x-8x

-8=6x

-8/6=x

-4/3=x

x=-4/3

Answer:

dial it up

2:16

simplify

1:8

now multiply 8 by the number of gigs

2:16

3:24

and so on.....

ring ring

1:9

again multiply the cost by the number of gigs

2:18

3:27

and so on....

Answer:

Length of ladder =L =15

Distance from wall = D =9

Height on wall = H =??

Pythagoras equation L*L = D*D + H*H

15×15= (9×9) + H×H

225-81 = 144 =HxH

H= 12 feet.

I am right or wrong

please check

Answer:

1x=3y

-9x=-2y

Step-by-step explanation:

6x=-4y

17x=-2y

4y

17x=-2y

Answer: 525

Step-by-step explanation:

450+15+60=525

Answer:

The cost of each ticket is $30.

Step-by-step explanation:

$450 is the total cost, so to get individual ticket prices you need to divide by the total number of drama club members.

450 ÷ 15 = 30

Answer:

the answer is 28 for A the answer for B is -5 for A, 15 for B, and -6 for C

Step-by-step explanation:

Answer:

5

Step-by-step explanation:

a^2 +b^2 = c^2

4^2 +3^2 =c^2

16 + 9 =c^2

25= c^2

5=c

Answer:

it would be 3 in the first box and 24 in the other

Step-by-step explanation:

because the ratio is 3 years to 24 montsh most of the time the larger number is on the left and the smaller number is on the right and 3 years is more than 24 months 24 months is only two years

Answer:(b) step 1

Step-by-step explanation:

The wrong step in the student's workings is step 1

The equation is given as:

x^2 - 2x - 8 = 0

Expand the equation

x^2 + 2x - 4x - 8 = 0

Factorize the equation

x(x + 2)- 4(x + 2)

Factor out x + 2

(x - 4)(x + 2) = 0

The above means that the factored equation of x^2 - 2x - 8 = 0 is (x - 4)(x + 2) = 0

This means that the step 1 of the student's step is wrong and incorrect

Read more about equations at:

https://brainly.com/question/2972832

#SPJ9

Answer:

The value for X is 25

Step-by-step explanation:

I hope this helps you out!