Raj and David save a same amount of money.David spent $120 buying a birthday gift for her friend.In the end Raj had 3 timesas much as David.How much does raj have?
Raj's money = 3 * David's money
r = 3d
David's money = Raj's money - $120
d = r - 120
Substitute.
r = 3 * (r - 120) Distribute.
r = 3r - 360 Subtract 3r from both sides.
r - 3r = -360
-2r = -360 Divide by -2
r = -360/-2
r = 180
Raj's money = $180