6+(1+9)=(6+1)+9

Solution for 6+(1+9)=(6+1)+9 equation:

6+(1+9)=(6+1)+9

We simplify the equation to the form, which is simple to understand 
6+(1+9)=(6+1)+9

Simplifying terms in parentheses
6+(+10)=(6+1)+9

Simplifying terms in parentheses
6+(+10)=(+7)+9

Remove unnecessary parentheses
+6+10=+(+7+)+9

Remove unnecessary parentheses
6+10=+7+9

We move all terms containing  to the left and all other terms to the right. 
0=+7+9-6-10

We simplify left and right side of the equation. 
0=0

0=0

This equation is an identity, so all real numbers are solutions.