Question

Sum of present age of two friends are 23 years , five years ago product of there age is 42 .Find there age 5 years hence

Answer 1

let x and y be age of 2 friends.

Since sum of present age i.e

x+y=23

and

five years ago their products was

(x-5)(y-5)=42

xy-5x-5y+25=42

xy-5(x+y)=42-25

xy-5*23=17

xy=17+115

xy=132

put x=23-y

y(23-y)=132

-y^2+23y=132

y^2-23y+132=0

from here we get y=11,12

also x=12,11

Now 5 year hence

add 5

So answer will be

17, 16