How do you factor $x^{2} - 13 x + 42$ $x^2 - 13x +42$ ?

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Answer 1 · 2015-05-25T22:38:09

Note that $(x - a) (x - b) = x^{2} - (a + b) x + (a \times b)$ $(x-a)(x-b) = x^2-(a+b)x+(axxb)$

Also note that $13 = 6 + 7$ $13 = 6 + 7$ and $42 = 6 \times 7$ $42 = 6 xx 7$

So $x^{2} - 13 x + 42 = (x - 6) (x - 7)$ $x^2-13x+42 = (x-6)(x-7)$

How do you factor x^2 - 13x +42x2−13x+42x^2 - 13x +42?