Answer:
Small candles cost 1 dollar, large candles cost 5 dollars.
Step-by-step explanation:
Let s represent small candles, L represent large candles.
You: 15 = 5s + 2L
Friend: 21 = 6s + 3L
Now you can solve for s and L, the cost of each candle type!
15 = 5s + 2L Multiply this equation by 3 -> 45 = 15s + 6L
21 = 6s + 3L Multiply this equation by 2 -> 42 = 12s + 6L
Now we have equal L's in both equations. Use elimination to get rid of L! Subtract the equations from each other.
45 = 15s + 6L
- 42 = 12s + 6L
------------------------
3 = 3s + 0L
Now solve for s.
3 = 3s
s = 1 dollar
Plug s back in to get L.
15 = 5s + 2L
15 = 5(1) + 2L
15 = 5 + 2L
10 = 2L
L = 5 dollars
