Please provide steps to factoring out this expression: x^3 y^2 - 9x^3 - 8y^2 + 72 Thanks much!
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Originally Posted by chopstixdcb Please provide steps to factoring out this expression: x^3 y^2 - 9x^3 - 8y^2 + 72 Thanks much! $\displaystyle x^3 (y^2-9)-8 (y^2-9)=0$ $\displaystyle (y^2-9)(x^3-8)=0$ Then here, make use of the identities: $\displaystyle a^2-b^2=(a+b)(a-b)$ $\displaystyle a^3-b^3=(a-b)(a^2+ab+b^2)$
So is this right? (x-2)(x^2+2X+4)(y+3)(y-3)(y+3)(y-3)?
Originally Posted by chopstixdcb So is this right? (x-2)(x^2+2X+4)(y+3)(y-3)(y+3)(y-3)? Why did you give an extra of 2 factors? The last 2?
I forgot, I understand now. The (y^2-9) allows me to group the (x^3-8). So I don't need those last two factors. Thanks so MUCH!
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