Let a and b be real numbers such that a + b = -1. Compute a^2 - b^2 + 3a + b.
a2 - b2 + 3a + b
Factor: (a + b)(a - b) + 3a + b
Sincea + b = -1: (-1)(a - b) + 3a + b
---> -a + b + 3a + b
2a + 2b
2(a + b)
2( -1)
-2
