algebra
posted by patricia .
I'm having difficulty solving 0.7y+9=y+15?????
I know the answer is 20 but can't remember procedure.
Do I change the decimal to a fraction 1st???

getting rid of decimals and fractions is usually a good first step. In this case, we get
7y + 90 = 10y + 150
3y = 60
y = 20
it could have been done without that. the procedure is to collect all the y's on one side, and the numbers on the other
.7y  y = 15  9
.3y = 6
y = 6/.3
y = 20