Since the centre is at the origin, (h, k) = (0, 0)
Hence, we can substitute h and k as 0 respectively.
General form:

Now, we know that (0, 4) lies on the circle. Thus, the radius must be 4 units.
So, our circle becomes:

Now, substitute (2, 6) to see if it lies on the circle.

Hence, it doesn't lie on the circle.
So basically all your doing is substituting the given number to the equation:
(3, ) (,0)
y=8(3)+2. 0=8x+2
y=24+2. 8x=0-2
y=26. 8x= 2
divide both side by 8
x=4
(3,26) (4,0)
Okay to find percentages of things you have to take that original value (1500) and multuply it by the percentage. But when you multiply you put the percentage into a decimal and move it over to the right side two decimal places to the left. For example 10.0% would mean you need to multiply by 0.10 okay?
So for this problem you need to do 1500 *.013 and you get 19.5 computers.
-12 ÷ 3 ×(-8 + (-4)^2 -6)+2
Order of operations (PEMDAS)
= -4 × (-8 + 16 - 6) + 2
= -4 × 2 + 2
= -8 + 2
= -6
Answer
-6