Lakota brought 6 new compact disk and 2 used compact disk for $127.92. At the same prices Mackenzie brought 3 new compact disk and 8 used compact disk for $133.89. Find the cost of buying a single used compact disk

the answer will be

step-by-step explanation:

  or  

sin y = 7/q

7 is the opposite side length, q is the hypotenuse

tan y = 7/r

7 is the opposite side length, r is the adjacent side length

using sohcahtoa ^^^^

cos y = adjacent/hypotenuse

cos y = r/q

i want the details r