Question

explain it please with each step

Answer 1

let the ages be 5x and 7x respectively
do not consider the next ages as x
5x+4/7x+4=3/4
cross multipy
4(5x+4)=3(7x+4)
20x+16=21x+12
16-12=21x-20x
4=x

5x=4*5=20
7x=7*4=28

therefore the ages are 20 and 28