Divide both sides by 4 to isolate x. We divide to undo the multiplication done to x. Note how 4x is the same as 4*x = 4 times x where x is a placeholder for a number.
If we divide both sides by 4, then we get...
4x < 48
4x/4 < 48/4
x < 12
Answer: Choice D) x < 12
