The ABE and DBC are both made of DBE and and ABD or EBC so if the firsts are equal than these are also equal
Recognize and represent proportional relationships between quantities. Decide whether two quantities are in a proportional relationship, e.g., by testing for equivalent ratios in a table or graphing on a coordinate plane and observing whether the graph is a straight line through the origin.
Answer:
10 tapes and 6 Cds
Step-by-step explanation:
As tapes sell for $10 and CD sell for $15, let t be the number of tapes bought and c the number of cds, we can write an equation for the expenditure in the form:
10c + 16t = expenditure
We also n=know she spent 220, so:
10c + 16t = 220
As she bought 16 items, the sum of CD and tapes must be equal to 16. So:
c + t = 16
If we take this last equation and subtract t in both sides:
c = 16 - t
We got the number of CD depending on the number of tapes. We can replace this in the first equation to get t:
10 [16 - t] + 16t = 220
160 - 10 t +16t = 220
160 + 6t = 220
If we subtract 160 in both sides
6t = 220 - 160
6t = 60
Dividing both by 6:
t = 60/6 = 10
So, she purchased 10 tapes. As in total she purchased 16 items she must have purchased 6 cds.
Solution: She purchased 10 tapes and 6 CDs