Let A represent Arthur L represent Lily -Arthur weighs 34 lb more than Lily, so we need to change this into equation: A=L+34 -Their combined weight is 180 lb less than 4 times Lily's weight A+L=4L-180 Then, we need to change A with L+34 into the second equation, and we have L+34+L=4L-180 2L+34=4L-180 Subtract 2L for both side 2L+34-2L=4L-180-2L 34=2L-180 Add 180 for both side 34+180=2L-180+180 214=2L Divided 2 for both side 214/2=2L/2 L=107 lb A=L+34 A=107+34 A=141 lbs Check: A=L+34 141=107+34 141=141 OK
A+L=4L-180 141+107=4(107)-180 248=428-180 248=248 True. As a result, Arthur weighs 141 pounds. Hope it help!