Question

S= Злrb + Злr2
solve for b?

Answer 1

`\large\boxed{b=(S)/(3\pi r)-1}`

Explanation:

`3\pi rb+3\pi r=S\qquad\text{divide both sides by}\ 3\pi r\\eq0\\\\(3\pi rb)/(3\pi r)+(3\pi r)/(3\pi r)=(S)/(3\pi r)\\\\b+1=(S)/(3\pi r)\qquad\text{subtract 1 from both sides}\\\\b=(S)/(3\pi r)-1`