D. Although I'm not 100% sure
The slope intercept form using the two points would be : y= 2x-13
We know that:

is an equation of a circle.
When we substitute x and y (from the pairs we have), we'll get a system of equations:

and all we have to do is solve it for a, b and r.
There will be:

From equations (II) and (III) we have:

and from (I) and (II):

Now we can easly calculate a and b:

Finally we calculate

:

And the equation of the circle is:
Because, if 6 + 6 = 12, then in 6 + 7, 7 can be splitted into 6 + 6 + 1, and so you find it easier...!!
Answer:
x= -3/5
Step-by-step explanation:
4x-2y=14
y=12x-1
4x-2(12x-1)=14
4x-24x+2=14
4x-24x=12
-20x=12
×= -12/20
x= -3/5