First you will subtract right to left and then what ur left with is the sum.
Perhaps you mean to find the volume under

? It seems like you have to rely on calculus otherwise (in the case that you indeed mean

).
Assuming this, note that

describes the top half of a sphere with radius 8, which means the volume below this surface over the disk

is simply half the volume of the sphere. Thus the volume is
X+10=15
Isolate x by subtracting 10 from both sides
x+10-10=15-10
x=5
Final answer: B
Check by plugging the value in
5+10=15
True
The arc is called B) Circle
A) x=2; i’m guessing if you meant by 4x+1=x+7