Evaluate for: a = 4, b = 8, c = -2
15). a (b + c) + b(a + c)


16).




Evaluate for: a = .5, b = 2, c = 4 (use a calculator!)
17). a b - 2 a c + a c = ______


18).
= ______



Evaluate for: a = 4, b = 9, c = -5

19).
= ______
20).
= ______