Question 148568
man=30
son=13
x=amount of years


13+x=(3/4)(30+x)


Distribute
13+x=22.5+3/4x


Subtract 13 from both sides
x=9.5+3/4x


Subtract 3/4x
1/4x=9.5


Multiply both sides by 4
x=38


38 years