Identify the variable(s), set up your equation(s), and solve. Richard has an elder sister who is twice his age and a younger sister who is two years younger than him. If the product of his sisters' ages is 70, how old is Richard?

Answers

Answer 1

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


Related Questions

describe the slope of the line passing through points A(-2,3) and B(4,-3)

Answers

Answer:

0/2 is ZERO is positive

Step-by-step explanation:

slope = y2 - y1 / x2 - x1

slope = -3 - 3 / 4 - (-2)

slope = -6/6

slope = -1

hope this helped :)

Please help me hahahhahahhahahhhhhhshshs can

Answers

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.

Which of the following finds T given I, P and R

Answers

Answer:

D. T= I/PR

Step-by-step explanation:

PRT are multiplyed so you divide PR to get T by itself.

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

Answers

Answer:

y=mx+b no judgement i think this is right but i coukldbe completely off

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 $4$?

Answers

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

Simplify 45 / 3 + 2 * 8 - 12 + 42

Answers

Answer:

61

Step-by-step explanation:

It’s 61 just do the calculation that’s what I did I hope this helped

Plz help me with this question
10 points

Answers

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.

What is 400,000 in scientific notation?
O A) 40 x 104
OB) 400 x 103
OC) 4 x 106
OD) 4 x 105

Answers

Answer:

4 x 10⁵

so that i think will be OD)

Does anyone know the answers this is Gina Wilson

Answers

Answer:yes

Step-by-step explanation:

Find the slope and the y-intercept of the graph of y
-4/5x - 2

Answers

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:

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

Answers

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

PLEASE HELP MEH NOW!! I WILL MARK BRAINLIEST 1/8 divided by 5

Answers

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'm more than 9 dozen and less than the number of days in 4 months. The sum of my digits is 11.

Answers

The answer would be 119

More than 9 dozen (9 x 12 = 108)

And

Less than the number of days in 4 months (4 x 30 = 120 or 4 x 31 = 124)

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:

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

Answers

The answer to the question is D

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

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))

Answers

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 = 0

Step-by-step explanation:

Given

α and β are roots of 4x²-5x-1=0

Then 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 = 0

7 + 5x = 2x + 25
step by step pls:(

Answers

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:

i'll mark you as brainliest​

Answers

Answer:

y = x - 2

Step-by-step explanation:

.

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

Answers

Answer:

it would be -18

Step-by-step explanation:

because you would divide 108 by 6 and you will get -18 each second

i'm doing a math worksheet and its asking me to describe the stair of a slope. what does that mean??

Answers

Answer:

i believe its the rise and the run of the slope.

Step-by-step explanation:

i believe its something similar to this photo

7a(3b - 2c + 4)


Help?

Answers

Answer:

21ab-14ac+28a

Step-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]

What is the ratio of 3:6

Answers

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!

Quadratic functions 2. Did I do it right

Answers

Yea you did, good job

Write 0.272727272727273 as a fraction in simplest form

Answers

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.​

Answers

Answer:55.6

Step-by-step explanation:

Answer:

55.6

Step-by-step explanation:

i need help on this please​

Answers

-6 answer to -4+(-2)

3 answer to 7+(-4)

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?

Answers

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!!

Find the percent of decrease from 27 to 18.
PLEASE HELP

Answers

-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 33.3

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.

Answers

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

Is the relation in the mapping below a function? Explain.
Domain
1,3,5,7
Range
2,4,6

Answers

Answer: No

Step-by-step explanation:

The range and the Domain aren’t equal

Can somebody plz answer this question quick and correctly!

WILL MARK BRAINLIEST WHOEVER ANSWERS FIRST :D

Answers

Answer:

42%

Step-by-step explanation:

100% - 58% = 42%

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