Answer:
X=quarts of water
Y=quarts of concentrate
Y=20 quarts of concentrate, X=80 quarts of water
Step-by-step explanation:
X=quarts of water
Y=quarts of concentrate
So X=4Y and water and concentrate make the lemonade so X+Y = quarts of lemonade
Then we have X=4Y and X+Y=100. Hence
X+Y=100 → 4Y+Y=100 → 5Y=100→ Y=20 quarts of concentrate → X=80 quarts of water