what is the shortcut formula for (x - 3)(x + 3)?

1 ⤊

what is the shortcut formula for (x - 3)(x + 3)?

please...

2007-09-19 13:25:38 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics

3 answers

Front
Outside
Inside
Last

(x-3)(x+3) multiply the two front numbers (x and x)=x^2
multiply the outside numbers (x and 3) = 3x
multiply the inside numbers (-3 and x) = -3x
multiply the last numbers (-3 and 3) = -9
so.......

x^2+3x-3x-9

x^2-9

2007-09-19 13:39:21 · answer #1 · answered by Logan w 2 · 0⤊ 0⤋

(a-b)(a+b) = aÂ²-bÂ²

So (x-3)(x+3) = xÂ²-9

2007-09-19 20:33:17 · answer #2 · answered by Pascal 7 · 1⤊ 0⤋

You mean what this comes out to be?

(x-3)(x+3)

Xsq+3x-3x-9

So it should be

Xsquared minus 9

if that is your question at least.

2007-09-19 20:40:23 · answer #3 · answered by Lloan 2 · 0⤊ 0⤋