How do you factor the expression $x^2 - 3x - 4$ ?

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Answer 1 · 2018-03-25T22:57:01

$(x-4)(x+1)$

We need to think of two numbers, that, when I add them, I get $-3$ , and when I multiply them, I get $-4$ .

Since their product is negative, the signs are different.

Through a little thought, and we deduce that our numbers are $-4$ and $1$ as

$-4+1=-3$ and $-4*1=-4$

Thus, our factored expression is

$(x-4)(x+1)$

How do you factor the expression x^2 - 3x - 4x^2 - 3x - 4?