SOLUTION: Solve by factoring and using the principle of zero products: x^2 + 4x - 21 = 0

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Question 370783: Solve by factoring and using the principle of zero products:
x^2 + 4x - 21 = 0
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2+%2B+4x+-+21+=+0
Just as the problem says, factor:
(x + 7)(x - 3) = 0
From the Zero Product Property we know that this (or any) product can be zero only if one (or more) of the factors is zero. So:
x+7 = 0 or x-4 = 0
Solving these we get:
x = -7 or x = 4