Question

The sum of two numbers is 8. if their sum is 4 times differene . find the number.

Answer 1

lets x and y be the two nos
then x+y=8
=x+y=4(x-y)
=x+y=4(x-y)
=8=4(x-y)
=2=x-y 
now equating we get -2y=2-8=-6
=y=3
substituting y
we get =x+3=8
=x=5