Question

9×+9+3×=15 e essa ?

Answer 1

12x= 15-9
X=6/12 ÷2
X=3/6

Answer 2

veja..

$9x+9+3x=15 \\ \\ 9x+3x=15-9 \\ \\ 12x=6 \\ \\ x= \frac{6}{12} \\ \\ simplificando \\ \\ x= \frac{1}{2}$