204k views
25 votes
HELP PLS ITS URGENT

three years ago, Melanie was 6 times as old as her brother Kevin, and in 5 years she will be only twice as old as Kevin. find their current ages

1 Answer

7 votes

Melanie: 15 years old

Kevin: 5 years old

Assume Kevin's present age is x.

That means that 3 years ago, his age would be x - 3.

Melanie's age would be 6(x - 3).

Same thing for 5 years into the future:

Kevin's age would be x + 5.

Melanie's age would be 2(x + 5).

The two equations we have here are:


\left \{ {{x + 5 = 2(x + 5)} \atop {x - 3 = 6(x - 3)}} \right.

By subtracting both equations, we are simplified to:

8 = -4x + 28

By solving the equation, we get x = 5.

That means that Kevin's current age is 5 years old.

Melanie's age could be calculated by substituting Kevins'.

6(x - 3) --> 6(5 - 3) --> 12

Since that was 3 years ago, you need to add 3 to 12 to get her current age.

12 + 3 = 15

Melanie's current age is 15 years old.

User Golkarm
by
8.2k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.