Last week a candle store received $423.60 for selling 20 candles. Small candles sell for $10.98 and large candles sell for $27.98. How many large candles did the store sell?

Answer 1

S + L = 20

1098S + 2798L = 42360

It is a toss up whether elimination or substitution is easier...I usually opt for the former

Multiply the 1st equation by 1098 and subtract: you'll get

1700L = 20400

and L = 12 so that S = 8

Answer 2

x+y = 20

10.98 x + 27.98 y = 423.60

10.98x + 27.98 ( 20 - x) = 423.60

10.98 x + 559.6 - 27.98x = 423.60

-17x = 423.60 - 559.60

-17 x = -136

x = 8

8 small and 12 large