X / 3 = 4 / b = y / 4 halla b si xy = 48?

X / 3 = 4 / b de donde x = 12 / b

y / 4 = 4 / b de donde y = 16 / b

entonces si x * y = 48 (12 / b) * (16 / b) = 48 (12 * 16) / b ^ 2 = 48 b ^ 2 = (12 * 16) / 48 b ^ 2 = 16 / 4 b ^ 2 = 4 b ^ 2 - 4 = 0 b ^ 2 - 2 ^ 2 = 0 (b - 2)(b + 2) = 0 de donde b - 2 = 0 = > b = 2 y b + 2 = 0 = > b = - 2

Prueba si b = 2 x = 12 / 2 = 6 y = 16 / 2 = 8 x * y = 48 6 * 8 = 48 48 = 48 si b = - 2 x = 12 / ( - 2) = - 6 y = 16 / ( - 2) = - 8 x * y = 48 ( - 6) * ( - 8) = 48 48 = 48.