3r plus 18 divided by 12 equals 4r - 48 divided by 4?

Answer 1

(3r + 18)/12 = (4r - 48)/4

Multiply both sides by 12: (3r + 18) = 3*(4r - 48)

or: 3r + 18 = 12r - 144

Subtract 3r from both sides: 18 = 9r - 144

Add 144 to both sides: 162 = 9r

Divide both sides by 9: 18 = r

Answer: r = 18