How do you solve $x^2 + 5x – 6 = 0$ ?

Question

1428 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-08-20T13:42:55

The solutions are

$color(green)(x=-6$

$color(green)(x=1$

$x^2+5x–6=0$

We can Split the Middle Term of this expression to factorise it and thereby find solutions.

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

$N_1*N_2 = a*c = 1*-6 = -6$

and

$N_1 +N_2 = b = 5$

After trying out a few numbers we get :

$N_1 = -1$ and $N_2 =6$

$6*-1 = -6$ , and $6+(-1)= 5$

$x^2+5x–6= x^2+6x-1x–6$

$x(x+6)-1(x+6)=0$

$(x+6)$ is a common factor to each of the terms

$color(green)((x+6)(x-1)=0$

We now equate factors to zero:

$x+6=0, color(green)(x=-6$

$x-1=0, color(green)(x=1$

How do you solve x^2 + 5x – 6 = 0x^2 + 5x – 6 = 0?