Question

Part A: You have $0.80 in your backpack in dimes and quarters. Let x represent the number of dimes and y represent the number of quarters. Write an equation in standard form that represents the situation
____x+____ y=____

Part B: You have $0.80 in your backpack in dimes and quarters. Let x represent the number of dimes and y represent the number of quarters. If you have 2 quarters in your backpack, how many dimes do you have?
______

Answer 1

Part A: 0.10x + 0.25 = 0.80 (dimes are 10 cents or 0.10 dollars, quarters are 0.25 dollars)
Part B: Plug in what you DO know and solve the one you DON’T:
0.10x + 0.25(2) = 0.80
0.10x + 0.50 = 0.80. Subtract 0.50 from both sides:
0.10x = 0.30 (Divide both sides by 0.10)
x = 3
Therefore you have 3 dimes