Answers

2016-07-06T10:33:31+08:00
(s+7)(s-3) = 0

s+7 = 0     |     s-3 = 0
s = 0-7      |     s = 0+3
s = -7        |     s = 3

s is equal to both -7 and 3
s = -7
s= 3
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