You can put this solution on YOUR website! x(x+1)=80
x^2+x-80=0
using the quadratic equation we get:
x=8.458 or -9.458.
NOTE: these are not integers.
IF these are even integers then:
x(x+2)=80
x^2+2x-80=0
(x+10)(x-8)=0
x-8=0
x=8 the smaller integer.
8+2=10 for the next integer.
proof
8(8+2)=80
8*10=80
80=80