How do you solve 6x^2 - 27x +27= 0 by factoring?

1 Answer
Aug 20, 2015

The solutions are
color(blue)(x=3/2

color(blue)(x=3

Explanation:

6x^2−27x+27=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 = 6*27 = 162
and
N_1 +N_2 = b = -27

After trying out a few numbers we get N_1 = -18 and N_2 =-9
-18*-9 = 162, and (-18)+(-9)=-27

6x^2−27x+27=6x^2−18x-9x+27
6x(x-3) -9(x-3) =0

(6x-9)(x-3) =0 is the factorised form of the expression.

We now equate each of these factors to the R.H.S (0)
6x-9=0, x=9/6,color(blue)(x=3/2
x-3=0, color(blue)(x=3