Advd costs twice as much as a music cd. jack buys 2 dvds and 2 cds and spends $45. determine how much one cd costs. in dollars

V=2c, and 2v + 2c =45 you can substitute v for 2c in the second equation because they equal to get 4c +2c =45 6c =45 c = 45/6, so the answer is $7.50

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!