# How do you factor #y= 4x^2 – 36x+ 81 # ?

##### 1 Answer

Dec 26, 2015

#4x^2-36x+81 = (2x-9)^2#

#### Explanation:

We can recognise this as a perfect square trinomial.

In general

In our example notice that

Hence:

#4x^2-36x+81 = (2x-9)^2#