Answer:
4pi
Step-by-step explanation:
area of a circle is pi*r^2
and you have diameter of 4
so 4/2 gives radius which is 2
A = pi*2^2 = 4pi
Solve for x over the real numbers:
-x^2 - 12 = -87
Add 12 to both sides:
-x^2 = -75
Multiply both sides by -1:
x^2 = 75
Take the square root of both sides:
Answer: x = 5 sqrt(3) or x = -5 sqrt(3) both Answers are correct
Any of 9's multiples besides 9 and 18 will work.
So: 27, 35, 45, 54 ,63, 72, 81, 90, 99, 108, 117, 126, 135, and so on