Cannot see your image, but the formula for the volume of a sphere is
V=(4/3)πr³
to solve for r: r³=v÷(4/3)π=v*3/(4π)=3v/(4π) (three v out of 4 pi)
r=∛(3v/4π)
r equals the cubic root of (three v over 4π)
(32x⁴ - 12x² + 7x) / 2x
32x⁴/2x - 12x²/2x + 7x/2x
16x³ - 6x + 7/2
So, Bob needs 2 cups of concentrate (I'll use the variable c to shorten it) for every 3.5 cups of water (w). When he has 6 cups of c, he has three times the original recipe, and therefore we need 3w as well.
3.5x2=6+1=7. So we need 7 cups of water.
Now, 6 cups of concentrate + 7 cups of water = 13 cups of orange juice.
Bob can make 13 cups of orange juice.
Hope I helped!