Answers

2015-01-09T14:07:11+08:00
To prove: do some FOIL method on both sides
2x(2x)+7(2x)-9(2x)+7(-9) = 2x(2x)+2(2x)-5(2x)-5(3)
4x²+14x-18x-63 = 4x²+4x-10x-15
then simplify both sides,
4x²-6x-63  =  4x²-6x-15
the equation is FALSE because the constants are not the same.
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2015-01-10T13:38:39+08:00
Here's some
(2x-9)(2x+7)=(2x-5)(2x+3)
2x(2x)+2x(7)-9(2x)-9(7)=2x(2x)+2x(3)-5(2x)-5(3)
4x2 + 14x- 18x - 63 = 4x2 + 6x - 10x - 15
4x2 - 4x - 63 = 4x2 - 4x - 15
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