2. If a^2-b^2=20 and a+b=2, what is the value of a-b?

I added the a^2-b^2+20 and a+b+20, but i couldn't get the answer to equal a-b.

Hey (a^2-b^2)= (a+b)(a-b) remember

forever
(a+b)(a-b) = 20
2(a-b) = 20
a - b = 10