Answers

2016-06-29T08:00:47+08:00
A.(2x + 3)(2x - 3)
F  - 2x (2x) = 4x²
O - 2x (-3) = -2x
I   - 3 (2x) = 6x
L  - 3 (-3) = -9

Add the Outer and the Inner
(-2x) + 6x = 4x

The answer is 4x²+4x-9.

B.(x+3)(x+5)
F  - x (x) = x²
O - x (5) = 5x
I   - 3 (x) = 3x
L  - 3 (5) = 15

5x + 3x = 8x

The answer is x²+8x+15.
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