Question

If 1/u= 1/8 - 1/5 is the formula Express f as the subject of the formula​

Answer 1

f = (uv)/(u + v)

Explanation:

1/u = 1/f - 1/v

Multiply both sides by ufv.

ufv(1/u) = ufv(1/f) - ufv(1/v)

fv = uv - uf

fv + uf = uv

f(v + u) = uv

f = (uv)/(u + v)