Solve the literal equation for y. a=9y+3y

To find Y, your equation will look like  y=(answer)

Start by COMBINING like terms-in this case, the "y's" 9y and 3y

Which will give you a=12y

Next, you want to get y by itself, so you need to DIVIDE by 12 (don't forget that you have to divide on both sides

a/12=12y/12

Your "12"s cancel out, leaving a/12=y and to make it consistent with the question and e format of linear equations: y=a/12