9 - x2 will factor into (3 - x)(3 + x)
x2-9x = x(x-9)
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x2-6x-27 = (x+3)(x-9) when factored
To factor any term, divide by the LCF (largest common factor) of the term. For 5x2-45, the LCF is 5. 5x2-45 = 5(x2-9) It can, of course, be factored even further to become: 5(x2-9) = 45(x2/9 - 1) but when factoring, we usually don't need to go past 5(x2-9) (for example, you've figured out that x2 = 9, thus x = +/- 3.)
X2 9 can be described mathematically to be a quadratic function.
x2 + 9 = 10x x2 - 10x + 9 = 0. (x - 9)(x - 1) = 0. Therefore, x = 1 or 9.
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d/dx (x2+ 9)1/2= 1/2*(x2+ 9)-1/22x = x(x2+ 9)-1/2or x/(x2+ 9)1/2
If: x2 = 81 Then: x = 9 or x = -9
9 - x2 will factor into (3 - x)(3 + x)
x2+24x+144 = 9 x2+24x+144-9 = 0 x2+24x+135 = 0 (x+9)(x+15) = 0 x = -9 or x = -15
First, it is important to regroup, so I am going to rearrange this equation: (x4 - 7x2 - 18 - 3x3 + 27x I can now factor the first three terms and the last two terms: (x4 - 7x2 - 18) becomes (x2 - 9)(x2 + 2) -3x3 + 27x becomes -3x(x2 - 9); so the new equation looks like: (x2 - 9)(x2 + 2) - 3x(x2 - 9) From here, factor out what is common, in this case- x2- 9. Therefore, you will have (x2 - 9)(x2 + 2 - 3x), which can be rearranged to (x2 -9)(x2 - 3x + 2). Further factoring reveals (x + 3)(x - 3)(x - 1)(x - 2) as the final answer.
x2-9x = x(x-9)
x2+2x-63 = (x-7)(x+9) when factored
The GCF is x2.