How do you factor completely $2x^2-x-10$ ?

Question

11407 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-05-23T13:11:39

$= color(blue)( (2x - 5) (x +2)$ is the factorised form of the equation.

$2x^2 - x - 10$

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:

$N_1*N_2 = a*c = 2*(-10) = -20$

AND

$N_1 +N_2 = b = -1$

After trying out a few numbers we get $N_1 = -5$ and $N_2 = 4$
$4* (-5) = -20$ , and $4+(-5)= -1$

$2x^2 - x - 10 = 2x^2 + 4x- 5x - 10$

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

$(x+2)$ is a common factor to each of the terms

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

How do you factor completely 2x^2-x-102x^2-x-10?