# How do you factor #121-22u+u^2# using the perfect squares formula?

##### 2 Answers

Given -

#121-22u+u^2#

#u^2-22u+121=0#

Take the constant term to the right

#u^2-22u=-121#

Take half of the coefficient of

#u^2-22u+121=-121+121#

#(u-11)^2=0#

#(u-11)(u-11)#

#### Explanation:

As the middle term is negative, let us **compare**

It is observed that

Question is can we have **.................(1)**

we also have last term

Question is can we have **.................(2)**

The decision whether we can have **(1)** and **(2)**

is based on third term i.e. whether

We can check it. As

and hence

**Once our understanding is clear we can do the entire in short** as the following

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