In order to find the cost of each CD, you would have to divide $38.04 by 4 CDs and you would get $9.51 as the cost of each CD. If you want to check if your answer is correct, you can either add $9.51 four times to get $38.04 or you can multiply $9.51 x 4 and you should get $38.04 remember that multiplication is always a way to check your answer for division problems and division is always a way to check an answer to your multiplicatiom problems. Just search it up for more info. Hope i helped! :)
What you have to do is add them all! 20 bar 11.4 2 11.4 weights 11.4 4.5 2 4.5 weights 4.5 450.0 4 450 weights 450.0 450.0 +450.0 --------- 1.8 10 200 +1,600 -------------- 1,811.8 is the answer