Question

Sum of 2 numbers is 20 and difference of squares is 100

Answer 1

let the numbers are x and y

then....

x+y= 20........eqn .1

x^2 - y^2 = 100
(x + y)(x - y) = 100
20(x-y) = 100
x - y= 100/20 =5......eqn.2

by eqn 1 and 2
x+y= 20
x - y= 5

2x = 25
x = 25/2
y = 20 -25/2
y = 15/2
answers are 25/2 , 15/2