Answers

2015-07-04T19:09:18+08:00
8x^2 + 16x = 42
8x^2 + 16x - 42 = 0
4x^2 + 8x - 21 + 0
(2x + 7) (2x - 3) = 0

equate to zero :
2x + 7 = 0
      2x = 7
        x = - 7/2

2x - 3  = 0
      2x = 3
       x = 3/2
1 5 1
2015-07-04T19:10:36+08:00
8x^2+16x=42
8x^2+16x-42=0
(4x-6)(2x+7)
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