Answer: Zero Product Property
Example:
x^2 + 5x + 6 = 0
(x+3)(x+2) = 0 .... factor
x+3 = 0 or x+2 = 0 ... zero product property used here
x = -3 or x = -2 .... solve each equation for x
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In general, the zero product property is that if A*B = 0, then either A = 0 or B = 0.