How do you factor $y= x^2 + 2x – 48$ ?

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Answer 1 · 2015-12-11T15:52:54

$color(blue)((x-6)(x+8)$ is the factorised form of the expression.

$y=x^2+2x-48$

We can Split the Middle Term of this expression to factorise it.

In this technique, if we have to factorise an expression like $ax^2 + bx + c$ , we need to think of 2 numbers such that:

$N_1*N_2 = a*c = 1*(-48) = -48$

AND

$N_1 +N_2 = b = 2$

After trying out a few numbers we get $N_1 = -6$ and $N_2 =8$

$8*(-6) = -48$ , and $8+(-6)= 2$

$y=x^2+color(blue)(2x)-48 =x^2+color(blue)(8x-6x)-48$

$=x(x+8) -6(x+8)$

$=color(blue)((x-6)(x+8)$

How do you factor y= x^2 + 2x – 48y= x^2 + 2x – 48?