Arthur weighs 54 lbs. more than Lily. Their combined weight is 280 lbs. less than 6 times Lily’s weight. How much does Arthur weigh?

Let lily's weight =L
Arthur's weight =L + 54
L + L + 54 =6L - 280, solve for L
2L - 6L = - 280 - 54
-  4L     = - 334
L = 83.50 lbs - Lily's weight
83.50 + 54 = 137.50 lbs - Arthur's weight.