Answers

2014-10-27T17:43:12+08:00
A=B
4x²-81
4(2)²-81
4(4)-81
16-81
= -65
(2x-9)(2x+9)
[2(2)-9][2(2)+9]
(4-9)(4+9)
(-5)(13)
= -65
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