Question

Dividir 21 em partes inversamente proporcionais a 9 e 12.

Answer 1

a/1/9 + b/1/12= 21
mmc 9 e 12 = 36
36/9 = 4......36/12 = 3
a/4+b/3 = (a+b)/7
a/4 + b/3 = 21/7
a/4 = 3.....a = 12
b/3 = 3.....b = 9