Answer :

6+8/10x=9/10x
subtract 8/10x from both sides
6=1/10x
multiply each side by 10
60=x
TSO
[tex]\sf 6+ \frac{8}{10} x= \frac{9}{10} x[/tex]
Subtract [tex]\frac{8}{10} x[/tex] from both sides

[tex]\sf 6+ \frac{8}{10} x - \frac{8}{10} x= \frac{9}{10} x- \frac{8}{10} x[/tex]

Simplify:
[tex]\sf 6 = \frac{1}{10}x[/tex]

Multiply 10 on both sides:
[tex]\sf 6 \times 10= \frac{1}{10}x \times 10[/tex]

Simplify
[tex]\sf 60= x [/tex]

So your answer is x=60. :)