Answer: not sure what you were trying to ask but two less than 15 is 13.
Answer:
y=2.5
Step-by-step explanation:
2y-6=-1
add 6 to negative 1 so that the 2y is all by itself
2y=5
divide 5 by 2
y=2.5
Let

then you will have a^2-12a+36=0 and then you can just factor to find a
The equation of a circle is: (x - h)² + (y - k)² = radius² where (h, k) is the center. Now just plug in your given information and simplify.
(x - 2)² + (y - 0)² = 9²
Your equation is:
(x - 2)² + y² = 81