Math

7y+4=3-2y

First, get all of the "y's" on one side of the equation
7y + 4 (+ 2y) = 3 - 2y (+ 2y)

Now, get the non-y factors on the other side of the equation
9y + 4 (- 4) = 3 (- 4)

You are left with
9y = -1

So,
y = - 1/9