We assume the two numbers are x and (x+1) so x^2+(x+1)^2=421 x^2+(x^2+2x+1)=421 2x^2+2x-420=0 According to the formula of quadratic x=14 or-15 cuz we know the two numbers are integers so x=14 therefore the other number is 15 To make sure that's correct 14^2+15^2=421