−12.7=y−3.4 can you guys me solve this.

For this case we have the following equation:
 
 From here, we must clear the value of y.
 For this, we follow the following steps:

 1) we add 3.4 on both sides of the equation:
 

 2) We rewrite the right side of the equation:
 

 3) We do the algebraic sum of the left side of the equation:
 

 Therefore, the solution of the equation is:
 

 
 y = -9.3