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horrorfan [7]
3 years ago
15

Peter is x years old and his sister is 5 years older. If the product of their ages is 84, form an equation in x and solve it to

find peter's age
Mathematics
1 answer:
daser333 [38]3 years ago
3 0

Answer:

x^2 + 5x - 84 = 0

x = 7

Step-by-step explanation:

let the sister's age = y

sister's age (y)  = 5 + x  equation 1

xy = 84  equation 2

Make y the subject of the formula in equation 2

y = 84/x

equate equation 1 and 2

84/x = 5 + x  equation 3

Multiply equation 3 by x

84 = 5x + x^2

x^2 + 5x - 84 = 0

tjis can be solved using quadratic equation

x^2 -7x + 12x -84 = 0

x(x + 12) -7(x + 12)

x = 7 or - 12

age cant be negative so his age is 7

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Answer:

i believe its C

Step-by-step explanation:


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3 years ago
joey ate 1/2 of the pie. molly ate 1/2 of what was left. lola ate 1/2 of what was lefet after molly finished. what fractional pa
anzhelika [568]
Molly ate 1/4 and then the last one is 1/8
8 0
3 years ago
Alvin takes pictures with his smartphone. Of the pictures 5/6 are animals. 3/4 of the animals are dogs. What fraction of the pic
ollegr [7]

Answer:

\dfrac{5}{8}

Step-by-step explanation:

Alvin takes pictures with his smartphone.

Of the pictures \frac{5}{6} are animals.

\frac{3}{4} of the animals are dogs.

To find which fraction of all pictures are pictures with dogs, you can simply multiply two fractions:

\dfrac{5}{6} \times \dfrac{3}{4} =\dfrac{15}{24} =\dfrac{5}{8}

<u>Another way</u> to solve this question:

Let the number of all pictures be 24 (divisible by both 4 and 6).

Then the number of pictures with animals is

\dfrac{5}{6} \times 24=5\times 4=20

and the number of pictures with dogs is

\dfrac{3}{4} \times 20=3\times 15

Hence, the fraction of pictures with dogs of all pictures is

\dfrac{15}{24}=\dfrac{5}{8}

8 0
3 years ago
Read 2 more answers
Please help, PLEASE will give brainlest answer
Korolek [52]

Answer:

SteAnswer:

y = 1/2x + 3/2

Step-by-step explanation:

Using the equation of the line

y - y_1 = m ( x - x_1)

First find the slope of the line

-2x + 4y = 8

It must be in this form

y = mx + C

4y = 8 + 2x

divide through by 4

4y/4 = 8 + 2x / 4

y = 8 + 2x/4

Let's separate

y = 8/4 + 2x/4

y = 2 + 1/2x

y = 1/2x + 2

Therefore, our slope or m is 1/2

Using the equation of the line

y - y_1 = m ( x - x_1)

With point (-5, -1)

x_1 = -5

y_1 = -1

y - (-1) = 1/2(x - (-5)

y + 1 = 1/2( x + 5)

Opening the brackets

y + 1 = x + 5 / 2

y = x + 5/2 - 1

Lcm is 2

y = x + 5 / 2 - 1/1

y = x + 5 -2/2

y = x +3/2

We can still separate it

y = x /2 + 3/2

y = 1/2x + 3/2

The equation of the line is

y = 1/2x + 3/2

The correct answer is A

brainliest?

8 0
3 years ago
What is the measure of CAD?
shusha [124]

I am pretty sure 52 degrees

7 0
3 years ago
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