Answer :
Answer/Step-by-step Explanation:
Given:
a = no. of DVDs
b = no. of CDs
Total cost ($) for DVDs and CDs = [tex] 2.5a + 2b [/tex]
a. The cost for 1 DVD = 2.5(a) = 2.5(1) = $2.5
The cost for 1 CD = 2(b) = 2(1) = $2
b. Total cost for 4 DVDs and 4 CDs:
Substitute a = 4, and b = 4 into the equation.
[tex] 2.5(4) + 2(4) [/tex]
[tex] 10 + 8 = 18 [/tex]
Total cost for 4 DVDs and 4 CDs = $18
c. To find out if $20 would be enough to buy 6 DVDs and 3 CDs, substitute a = 6, and b = 3 into the equation. Solve for the total cost to see if it equals $20 or is less than $20. If it's greater than $20, then it won't be enough.
[tex] 2.5(6) + 2(3) [/tex]
[tex] 15 + 6 = 21 [/tex]
6 DVDs and 3 CDs cost more than $20, therefore, $20 is not enough.