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

your mom x 3

step-by-step explanation:

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.