Question 906792
a - b = 2
a^2+b^2=20
a=b+2
(b+2)^2+b^2=20
b^2+4b+4+b^2=20
2*b^2+4b+4=20
2*b^2+4b-16=0
b^2+2b-8=0
(b+4)*(b-2)=0
b=4 or b=-2
so we have two sets of answers
4 and 2
and
-2 and -4
I liked the other tutor's logical approach but it left out the negative numbers.