Question

Solve for lower case f

Answer 1

f = (Fd-Fg)/(F+g)

Explanation:

Cross multiply

Ff+Fg-Fd = -fg

Ff+fg = Fd-Fg

Factorise the left side

f(F+g) = Fd-Fg

divide both sides by F+g

f = (Fd-Fg)/(F+g)