# How do you solve #r^2 - 9r - 38 = -9# by completing the square?

##### 1 Answer

Given

First add 9 to both sides to get:

Then

Adding

So:

Add

In general:

which is zero when

and hence

so

Subtracting

Does that look familiar?

May 19, 2015

Given

First add 9 to both sides to get:

Then

Adding

So:

Add

In general:

which is zero when

and hence

so

Subtracting

Does that look familiar?