Let a and b be rea numbers such that a + b = -1. Compute a^2 - b^2 + 2a.
One way to solve this is to just plug in a = 0, b = -1, but let's also do it algebraically.
a^2 - b^2 + 2a
(a+b)(a-b) + 2a
-1(a-b) + 2a
b-a + 2a
a+b
-1
:))
=^._.^=
