Answer:Let x be the number of full cup sold Let y be the number of half cup sold Whether the cup was full or not, they used 37 cups. Therefore, x + y = 37 How much money did they make selling half cup lemonade? They made y × 0.25 How much money did they make selling full cup lemonade? They made x × 0.50 Money made selling full cup + money made selling half cup = 15 x × 0.50 + y × 0.25 = 17 You end up with a system of linear equation to solved x + y = 37 x × 0.50 + y × 0.25 = 17 x + y = 37 equation 1 0.50x + 0.25y = 17 equation 2 Solve for y in equation 1 x + y = 37 x - x + y = 37 - x y = 37 - x Replace y in equation 2 0.50x + 0.25 (37 - x) = 17 0.50x + 0.25 × 37 - 0.25x = 17 0.50x + 9.25 - 0.25x = 17 0.25x + 9.25 = 17 0.25x + 9.25 - 9.25 = 17 - 9.25 0.25x = 17 - 9.25 0.25x = 7.75 Divide both sides by 0.25 0.25x/0.25 = 7.75/0.25 x = 31 y = 37 - x = 37 - 31 = 6 Sasha and Francisco sold 31 full cup and 6 half cup of lemonade It seems like people love their lemonade
