Question

3 +4=5
¨¨ ¨¨ ¨¨
x 9 12

Answer 1

$\frac{3}{x} \ + \ \frac{4}{9} \ = \ \frac{5}{12}$

Fazendo o MMC:

$\frac{108 \ + \ 16x \ = \ 15x}{36x}$

108 + 16x = 15x
108 = 15x - 16x

-x = 108 .(-1)

x = -108