16 - 12x = 4y
First, divide both sides by 4. / Your problem should look like:

= y
Second, factor out the common term 4. / Your problem should look like:

= y
Third, cancel 4. / Your problem should look like: 4 - 3x = y
Fourth, switch sides. / Your problem should look like: y = 4 - 3x
Answer:
y = 4 - 3x