Question

The difference of the squares of two consecutive integers is 21. find the integers.

Answer 1

let the two integers be x and x+1
(x+1)^2-x^2=21
x^2+2x+1-x^2=21
2x+1=21
2x=20
x=10
then x=10, x+1
10+1=11
the two integers are 10, 11