Answer:
0.6y+1.2=0.3y-0.9+0.8y
+0.9= +0.9
0.6y+2.1=1.1y
-0.6y=-0.6y
2.1=0.5
y=4.2
Explanation:
First you want to isolate the variable to one side which is exactly why I added 0.9 to both sides. Then you want to combine like terms. By combining like terms you can now distribute the variable by the value remaining, which led to me getting y=4.2