Answer:
x = 6
Step-by-step explanation:
[tex]\frac{9+x}{3x} = \frac{5}{6}[/tex]
6(9+x) = 5(3x)
6*9 + 6*x = 5*3x
54 + 6x = 15x
54 = 15x - 6x
54 = 9x
x = 54/9
check:
(9+6)/(3*6) = 5/6
15/18 = 5/6
