Joel needs to buy some blank dvds and zip disks to back up a large amount of data that has been generated by an accounting firm. he buys 6 dvds and 3 zip disks for $96. he later realised these are not sufficient and so guys another 5 dvds and 4 zip disks for $116. how much did each dvd and each zip disk cost? (assume the rate per item was changed for each visit). show working.

D = 4, Z = 24

Step-by-step explanation:

6D+3Z = 96

5D+4Z = 116

multiply top by 5 and bottom by -6

top equation = 30D+15Z = 480

bottom equation = -30D-24Z = -696

Cancel 30D and -30 D

top equation  = 15Z = 480

Bottom equation = -24Z = -696

15Z - 24 Z = 480 - 696

-9Z = 216

Z = 216/9

Z = 24

Now that we have the value of Z, we can substitute it in any equation to find D

6D + 3(24) = 96

6D + 72 = 96

6D = 96 - 72

6D = 24

D = 24/6

D = 4

susie has 7 apples

-9

step-by-step explanation: