How do you factor $x^2y^2 - 17xy^2 + 72y^2$ ?

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Answer 1 · 2015-05-24T23:44:41

Notice that all of the terms are multiples of $y^2$ .

Also notice that $72 = 8 xx 9$ , while $17 = 8 + 9$ .

So:

$x^2y^2-17xy^2+72y^2$

$=y^2(x^2-17x+72)$

$=y^2(x-8)(x-9)$

How do you factor x^2y^2 - 17xy^2 + 72y^2x^2y^2 - 17xy^2 + 72y^2?