Half of the difference between 30 percent of a minus 4 equals 20 percent of a plus 6

Half of the difference between 30 percent of a minus 4 equals 20 percent of a plus 6

1/2(30%a-4)=20%a+6
30%a-4=2(20%a+6)
30%a-4=40%a+12
-12-4=40%a-30%a
-16=10%a
a= -160