Question 427099
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Hi
factoring
a^2+7a+12=0
(a+4)(a+3)= 0
Note:SUM of the inner product(4a) and the outer product(3a) = 7a
(a+4)=0    a = -4
(a+3)= 0   a = -3

CHECKING our Answer*** SUBSTITUTING our Answers back into the original Equation
a^2+7a+12=0
16 -28 + 12 = 0  |checking a = -4
9  -21 + 12 = 0  |checking a = -3