How do you factor $y= 2x^2 + 13x + 15$ ?

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Answer 1 · 2015-12-10T05:27:40

$color(blue)((2x+3) (x+5)$ is the factorised form of the expression.

$y=2x^2+13x+15$

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:

$N_1*N_2 = a*c = 2*15 =30$

AND

$N_1 +N_2 = b = 13$

After trying out a few numbers we get $N_1 = 10$ and $N_2 =3$
$10*3 =30$ , and $10+3 = 13$

$2x^2+color(blue)(13x)+15 =2x^2+color(blue)(10x +3x)+15$

$=2x(x+5) +3(x+5)$

$= color(blue)((2x+3) (x+5)$

How do you factor y= 2x^2 + 13x + 15 y= 2x^2 + 13x + 15 ?