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.