Answer:
7 years
Step-by-step explanation:
Given that:
Let Richard's age = x
Elder sister's age = 2x
Youngwr sister's age = x - 2
Product of sisters ages = 70
2x * (x - 2) = 70
2x² - 4x = 70
2x² - 4x - 70 = 0
x² - 2x - 35 = 0
x² - 7x + 5x - 35 = 0
x(x - 7) +5(x - 7) = 0
(x - 7) or (x + 5) = 0
x = 7 or x = - 5
X can't be negative
Hence, x = 7
Richard is 7 years
1. To graph any linear equation in the calculator it needs to be in the slope
y intercept form. What is the slope y-intercept form for the equation
4y – 20x = -8
Answer:
y=mx+b no judgement i think this is right but i coukldbe completely off
Step-by-step explanation:
Find the slope and the y-intercept of the graph of y
-4/5x - 2
Answer:
slope - (-4/5)
y- intercept - (0,-2)
Step-by-step explanation:
Answer:
the slope is -4/5 and the y intercept is -2
Step-by-step explanation:
A mosquito is walking at random on the nonnegative number line. She starts at $1$. When she is at $0$, she always takes a step $1$ unit to the right, but, from any positive position on the line, she randomly moves left or right $1$ unit with equal probability. What is the expected number of times the mosquito will visit $0$ before the first time she visits $4$?
The expected number of times the mosquito will visit 0 before the first time she visits 4 is 3/4 by using concept of probability and geometric series.
Given that repeatedly throwing a fair tetrahedral die, trying to get a 4 (success) before getting a number from 1 to 3 (failure), which follows a geometric distribution.
To find the expected number of visits to 0 before reaching 4, analyze two cases:
success (reaching 4 before 0) and failure (reaching 0 before 4).By the given data, the probabilities of two cases are:
P(success) p = 1/4,
P(failure)=3/4.
The expected count of failures, X, can be found in terms of success probability p as
[tex]E[X]=\sum_{x=0}^{+\infty}[x(1-p)^xp][/tex]
On substituting p = 1/4 gives:
[tex]E(X) = 0(1/4)+1(3/4)(1/4)+2(3/4)^2(1/4)+3(3/4)^3(1/4)+.........[/tex]
On taking (1/4) gives
[tex]E(X) = 1/4[3/4+(3/4)^2+(3/4)^3+......+\infty]----(1)[/tex]
Consider [tex]3/4+(3/4)^2+(3/4)^3+......+\infty[/tex]
This forms a geometric series tends to infinity and the sum is given by :
[tex]S_\infty = a/(1-r)[/tex]
Here: a= 3/4
r = 3/4
Plugging these values into formula gives:
[tex]3/4+(3/4)^2+(3/4)^3+......+\infty = S_\infty[/tex]
[tex]S_\infty= 3/4/(1-3/4)[/tex]
On subtracting the denominator gives:
= 3/4/(1/4)
On taking reciprocal gives:
= 3/4 * 4
On simplifying gives:
= 3
Substituting these value into given equation 1 gives:
E(X) = 1/4*[3]
On multiplying gives:
E(X) = 3/4.
Therefore, the expected number of times the mosquito will visit 0 before the first time she visits 4 is 3/4 by using concept of probability and geometric series.
Learn more probability about here:
https://brainly.com/question/23846068
#SPJ4
i need help on this please
7 + 5x = 2x + 25
step by step pls:(
Answer:
x = 6
Step-by-step explanation:
7 + 5x = 2x + 25
first subtract 7 from both sides to isolate 5x on the left
5x = 2x + 18
then subtract 2x from both sides to isolate all of the x terms to one side
3x = 18
then divide 18 by 3 to solve for x
x = 6
hope this helped!! :)
Answer:
i got you, i wrote it out and all gimme brilliantness
Step-by-step explanation:
What is 400,000 in scientific notation?
O A) 40 x 104
OB) 400 x 103
OC) 4 x 106
OD) 4 x 105
Answer:
4 x 10⁵
so that i think will be OD)
i'm doing a math worksheet and its asking me to describe the stair of a slope. what does that mean??
Answer:
i believe its the rise and the run of the slope.
Step-by-step explanation:
i believe its something similar to this photo
What is the ratio of 3:6
Answer:
1:2
Step-by-step explanation:
You didn't really specify, but I'm going to assume you meant as simplified as possible. If you write it as a fraction, it will be ½ or as a decimal it will be 0.5.
Answer:
1:2
Step-by-step explanation:
Simplifying a ratio is like simplifying a fraction.
Simply put the number to the left as the numerator, and the number to the right as the denominator.
In this case, 3/6 = 1/2.
Hence, plug the numbers right back in and you get 1:2.
Hope this helped!
HELLPP. ITS URGENT.50 PTS
Please show working.
Question : If α and β are roots of the quadratic equation : 4x²-5x-1=0, find the quadratic equation whose roots are :
(See image for full question . No (IV) and (v))
Answer:
I replaced alpha by A and bitta by B. Sorry for this mistake
Answer:
4x² - 13x + 8 = 04x² - 11x + 5 = 016x² - 41x + 1 = 0x² + 5x + 4 = 0x² - 66x + 64 = 0Step-by-step explanation:
Given
α and β are roots of 4x²-5x-1=0Then the sum and product of the roots are:
α+b = -(-5)/4 = 5/4αβ = -1/4(i) Roots are α + 1 and β + 1, then we have:
(x - (α + 1))(x - (β + 1)) = 0(x - α - 1)(x - β - 1) = 0x² - (α+β+2)x + α+β+ αβ + 1 = 0x² - (5/4+2)x +5/4 - 1/4 + 1 = 0x² - 13/4x + 2= 04x² - 13x + 8 = 0(ii) Roots are 2 - α and 2 - β, then we have:
(x + α - 2)(x + β - 2) = 0x² + (a + β - 4)x - 2(α + β) + αβ + 4 = 0x² + (5/4 - 4)x - 2(5/4) - 1/4 + 4 = 0x² - 11/4x - 10/4 - 1/4 + 16/4 = 0x² - 11/4x + 5/4x = 04x² - 11x + 5 = 0(iii) Roots are α² and β², then:
(x - α²)(x-β²) = 0x² -(α²+β²)x + (αβ)² = 0x² - ((α+β)² - 2αβ)x + (-1/4)² = 0x² - ((5/4)² -2(-1/4))x + 1/16 = 0x² - ( 25/16 + 1/2)x + 1/16 = 0x² - 33/16x + 1/16 = 016x² - 33x + 1 = 0(iv) Roots are 1/α and 1/β, then:
(x - 1/α)(x - 1/β) = 0x² - (1/α+1/β)x + 1/αβ = 0x² - ((α+β)/αβ)x + 1/αβ = 0x² - (5/4)/(-1/4)x - 1/(-1/4) = 0x² + 5x + 4 = 0(v) Roots are 2/α² and 2/β², then:
(x - 2/α²)(x - 2/β²) = 0x² - (2/α² + 2/β²)x + 4/(αβ)² = 0x² - 2((α+β)² - 2αβ)/(αβ)²)x + 4/(αβ)² = 0x² - 2((5/4)² - 2(-1/4))/(-1/4)²x + 4/(-1/4)² = 0x² - 2(25/16 + 8/16)/(1/16)x + 4(16) = 0x² - 2(33)x + 64 = 0x² - 66x + 64 = 0Quadratic functions 2. Did I do it right
After being exposed to an incredible shrinking machine, Halley's height decreased by 108 cm over 6 seco
by the same amount each second. How much did Halley's height change each second?
18 cm
B
108 cm
-18 cm
D
-108 cm
Answer:
it would be -18
Step-by-step explanation:
because you would divide 108 by 6 and you will get -18 each second
Is the relation in the mapping below a function? Explain.
Domain
1,3,5,7
Range
2,4,6
Answer: No
Step-by-step explanation:
The range and the Domain aren’t equal
Find the percent of decrease from 27 to 18.
PLEASE HELP
-33.33333333333333 %A change from 27 to 18 represents a negative change (decrease) of -33.33333333333333%
Use the formula found below on this webpage to find the percent changeby replacing the given values:Percent change = New - Old|Old| 100%Percent change = 18 - 27|27| x 100 = -927 x 100 = -33.33333333333333decrease)
Where: 27 is the old value and 18 is the new value. In this case we have a negative change (decrease) of -33.33333333333333 percent because the new value is smaller than the old value.
The Answer is: -33.33333333333333% or 33.3Which of the following finds T given I, P and R
Answer:
D. T= I/PR
Step-by-step explanation:
PRT are multiplyed so you divide PR to get T by itself.
PLEASE HELP MEH NOW!! I WILL MARK BRAINLIEST 1/8 divided by 5
Answer:
1/40 or .025
Step-by-step explanation:
Just flip the 5 then multiply instead of dividing.
[tex]\frac{1}{8}*\frac{1}{5}[/tex]
You turn 5 into 1/5 by flipping it.
When you multiply them you get.
[tex]\frac{1}{40}[/tex]
or
.025
Hope this helps! Have a blessed day!
i'll mark you as brainliest
Answer:
y = x - 2
Step-by-step explanation:
.
A cuboid with a volume of 925cm^3 has dimensions.
4cm, (x + 1) cm and (x + 11) cm.
Show clearly that x^2 + 12x - 220 = 0
Solve the equation by factorising, making sure you show the factorisation.
State both values of x on the same line.
Finally, find the dimensions of the cuboid, writing all three on one line.
Answer:
Step-by-step explanation:
Volume of the cuboid = Length * Width * Height
Given
Length = 4cm
Width = (x+1)cm
Height = (x-11)cm
Volume of the cuboid = 4(x+1)(x+11)
Volume of the cuboid = 4(x^2+11x+x+11)
Volume of the cuboid = 4(x^2+12x+11)
Volume of the cuboid = 4x*2+48x+44
925 = 4x*2+48x+44
4x*2+48x+44-925 = 0
4x*2+48x-881 = 0
Divide through by 4
x^2 + 12x - 220.25 = 0
Factorize using the general formula;
x = -12±√12²-4(-220.25)/2
x = -12±√144+881/2
x = -12±√1025/2
x = -12±32/2
x = 12+32/2
x = 20/2
x = 10
Hence the dimension of the cuboid is 4cm, (10+1)cm and (10+11)cm
Dimension is 4cm by 11cm by 21cm
describe the slope of the line passing through points A(-2,3) and B(4,-3)
Answer:
0/2 is ZERO is positive
Step-by-step explanation:
Does anyone know the answers this is Gina Wilson
Answer:yes
Step-by-step explanation:
Liberty bought a make-your-own salad when she went out to lunch at a restaurant. The salad cost $4, plus $0.85 for each salad topping. Liberty spent $9.95 on the salad. Which equation can be used to find t, the number of toppings that Liberty ordered on her salad
I believe you answer would be $4 + $0.85t =$9.95
Answer:
7
Step-by-step explanation:
c = $0.85t+$4
$9.95 = $0.85t+$4
$9.95-$4 = $0.85t
$5.95 = $0.85t
$5.95/$0.85 = t
7 = t
Plz help me with this question
10 points
9514 1404 393
Answer:
The sequence 18
Step-by-step explanation:
After Nolan brings down a zero, the dividend Nolan will be 20, the same one he started with. So, he will get the same result he has gotten so far: the first quotient digit is 1 and the second quotient digit is 8, resulting in a new dividend of 20 (after the 0 is brought down).
The digits 18 will repeat until Nolan gets tired.
Write 0.272727272727273 as a fraction in simplest form
Answer:
27/100?
Step-by-step explanation:
In triangleABC, a = 1.4 cm, b = 1.5 cm and c=1.5 cm. Find the measure of angleA to the nearest 10th of a degree.
Answer:55.6
Step-by-step explanation:
Answer:
55.6
Step-by-step explanation:
Please help me hahahhahahhahahhhhhhshshs can
Answer:
The slope of this line is -2/3x.
Step-by-step explanation:
The slope can be found by getting x1 and y1 (0,3) and x2 and y2 (3,1). Once you have these you would do y2 - y1 / x2 - x1.
And the equation then is
1 - 3 / 3 - 0. After simplifying this you get -2/3.
7a(3b - 2c + 4)
Help?
Answer:
21ab-14ac+28aStep-by-step explanation:
[tex]7a(3b - 2c + 4)\\\\\mathrm{Distribute\:parentheses}\\\\=7a\times \:3b+7a\left(-2c\right)+7a\times\:4\\\\\mathrm{Apply\:minus-plus\:rules}\\\\+\left(-a\right)=-a\\\\=7\times\:3ab-7\times\:2ac+7\times\:4a\\\\Simplify\\\\21ab-14ac+28a[/tex]
Simplify 45 / 3 + 2 * 8 - 12 + 42
Answer:
61
Step-by-step explanation:
Pythagorean theorem: Manuel purchases a rectangular picture
frame that has a diagonal measure of
17 inches and a height of 8 Inches. What is
the width of the picture frame?
Answer:
width = 15
Step-by-step explanation:
a² + b² = c² This the the formula
(PLUG IN)
8² + b² = 17²
64 + b² = 289 (subtract 64 on both sides)
b² = 225 (square root)
b = 15
Hope this helps ya!!
I'm more than 9 dozen and less than the number of days in 4 months. The sum of my digits is 11.
Answer: 92 or 119
in 4 months, 2 months with 30 days per month, 2 months with 31 days per month
suppose: the number to find is X
have: 90 < X < 30.2 + 31. 2 ⇔ 90 < X < 122
if X is a number has 2 digits => X is xy
=> [tex]\left \{ {{x+y=11} \atop {90<x\leq 100}} \right.[/tex]
=> xy = 92
if X is a number has 3 digits => X is abc
we have: [tex]\left \{ {{a+b+c=11} \atop {100\leq abc<122}} \right.[/tex]
because 100 ≤ abc < 122 => a = 1; b = 0 or 1
+) if a =1 ,b = 0 but a+ b +c = 11 => c = 10 (removed because c is a 1-digit number)
+) if a = 1, b = 1 => c = 9
=> abc = 119
=> X is 92 or 119
Step-by-step explanation:
Can somebody plz answer this question quick and correctly!
WILL MARK BRAINLIEST WHOEVER ANSWERS FIRST :D
Answer:
42%
Step-by-step explanation:
100% - 58% = 42%
Which equation is true for the value b= 10?
O A.
2(b + 4) = 16
O B.
2(b + 2) = 40
O C.
3(b- 2) = 24
OD
2(8 + b) = 42
OE.
3(b - 4) = 20
Answer: C. 3(b-2)=24
Step-by-step explanation: See since b equals ten and by the rules of P.E.M.D.A.S the parenthesis/brackets comes first so 10-2 equals 8 and three times 8 is 24 therefore the answer is 24