Answer/Step-by-step Explanation:
Given:
a = no. of DVDs
b = no. of CDs
Total cost ($) for DVDs and CDs = 
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.


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.


6 DVDs and 3 CDs cost more than $20, therefore, $20 is not enough.
-3x-2y=30
-2y=3x+30
y=-3/2x-15
the answer is y=-3/2x-15
Sum of those two angles = 180 - 100 = 80
Now, Total ratio = 3 + 5 = 8
Amount of 1 unit = 80 / 8 = 10
Angle measures: = 3(10) & 5(10) = 30, 50
In short, Your Answer would be 30 & 50
Hope this helps!
Divide both the numerator and the denominator by 7, that would give you ⅜
A = # of adults = 3
s = # of students = 5
9(3) + 6(5) =
27 + 30 =
57