Hello!
In this problem, Erica get 3 dollars for each movie ticket bought, and 80 cents for each meal. Before creating an equation, we can assign some variables.
m can be represented as number of meals
t can be represented as number of tickets
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Part A: Create an equation.
For every ticket, Erica gets three dollars, which is shown by 3t. While for every meal, Erica gets 80 cents, which is shown by 0.80m. Also, last month, Erica earned 18 dollars in total. With that information, we can create our equation:
3t + 0.80m = 18
Part B: Solve this equation justifying each step.
3t + 0.80m = 18
3t + 0.80(15) = 18 (substitute the known values into the variable m)
3t + 12 = 18 (use the distributive property)
3t = 6 (subtract 12 from both sides)
t = 2 (divide both sides by 3)
Part C: How many movie tickets did Erica purchase?
From the work shown above, Erica bought two tickets last month.