Let a be greater than 0, B be greater than 0, a + B = 1; prove that 1 of a + 1 of B + 1 of AB is greater than or equal to 8

Let a be greater than 0, B be greater than 0, a + B = 1; prove that 1 of a + 1 of B + 1 of AB is greater than or equal to 8

A + B = 1 > = 2 radical (AB)
ab = 2/(1/4) = 8