Josh weight 66 pounds and Ben weighs 78 pounds.
Using x to represent Josh's weight, the formula is
x + (x + 12) = 144. Combine like terms to make 2x + 12 = 144. Subtract 12 from each side so that 2x = 132. Finally, divide both sides by 2 to get x = 66, which is Josh's weight. Add 12 pounds to find Ben's weight, which is 78 lbs.