Question

Mack is 3 times as old as Justin. In 3 years, Mack's age will be 5 more years more than 2 times as old as Justin. How old are Mack and Justin?

What is the system of equation for this?
I got 3x=7 and x=5+2y. But it's wrong because, I ended up with negatives.
Help! Thx.

Answer 1

First you have to define your variables.
your equations have no relation to the English sentences.

Let Justin's present age be x
then Mack's present age is 3x , (no need to use 2 variables)

In 3 years time:
Justin will be x+3
Mack will be 3x+3

now translate the English into math
"Mack's age will be 5 more years more than 2 times as old as Justin"
3x+3 = 2(x+3) + 5

this solves easily to
3x+3 = 2x + 6 + 5
x = 8, and then 3x = 24


Justin is now 8
Mack is now 24

check:
in 3 years ...
Justin is 11
Mack is 27

is 27 five more than twice 11 ??
2(11) + 5 = 27
YEAHH!