# Let x,y be real numbers and #y^2+4y+9x^2-30x+29=0#, which of the following is equal to #9x-y#? A. 17 B. 25 C. 30 D. 41

##### 1 Answer

Jun 17, 2018

A

#### Explanation:

You may notice that it bears some similarities to a circle with the general form

So first up, you need to complete the square

In case you don't remember how to complete the square,

Therefore, the centre is

Now you have the equation