Question 21437
Solve for b:
{{{(b+a)/ab = 1/f}}} Multiply both sides by ab.
{{{a+b = ab/f}}} Multiply both sides by f.
{{{af + bf = ab}}} Subtract bf from both sides.
{{{af = ab - bf}}} Factor b from the right side.
{{{af = b(a-f)}}} Divide both sides by (a-f).
{{{af/(a-f) = b}}} or {{{fa/(a-f)}}}