A girl is twice as old as her sister. Five years hence, the product of their ages (in years) will be 375. Find their present ages. A girl is twice as old as her sister. Five years hence, the product of their ages (in years) will be 375. Find their present ages.

girls=20, sister=10

Step-by-step explanation:

Let x = the girl's sister's age (present)

Let 2x= the girl's age (present)

According to the question

(x+5)(2x+5)=375

Expand parentheses by FOIL (First Outer Inner Last)

2x²+5x+10x+25=375

Combine like term (5x and 10x)

2x²+15x+25=375

Subtract 375 on both sides

2x²+15x+25-375=375-375

2x²+15x-350=0

Find the factors (cross factor)

(x-10)(x+17.5)=0

x=10 or x=-17.5 (rej) ⇔ the age can't be negative

the girl's age is 20, and her sister's age is 10.

question 1 is 8, question 2 is 9, question 3 is 24

step-by-step explanation:

now, the numbers they give you at the top are the key. from there, you just have to plug and chug! let's try 1, 2, and 3!

key: a=3, b=5, c=6

1. a+5

remember, a=3, so we plug that in to get 3+5=8

2. 15-c

c=6, so we plug that in to get 15-6=9

3. 4b

b=6, so we plug it in to get 4*6=24

time to try the rest on your own! if you put the answers below in a comment, i'll check them for you!