my lesson says to find the unknown number in each equation.

12r - 4r = 48
r=?
could the answer be r=48? or r=8x6

r is not 48

r = 48 divided by 8

What is 48 divided by 8?

12r - 4r = 8r

That means that 8 times some number equals 48

What is that number? What times 8 = 48?