Respuesta :

Answer:

  • f = ab/(a + b)

Step-by-step explanation:

#14

Given:

  • 1/f = 1/a + 1/b

Solving for f:

  • 1/f = b/ab + a/ab
  • 1/f = (a + b)/ab         cross - multiply
  • f(a + b) = ab             divide by (a + b)
  • f = ab/(a + b)