Given the equation 6x + 18 = 72:
Part A: Write a short word problem about a purchase made to illustrate the equation.
Part B: Solve the equation showing all work.
Part C: Explain what the value of the variable represents.
Part A: John went to a store and bought some items. Each item costs $6 and he also had to pay a fixed fee of $18. After the purchase, John had a total bill of $72. How many items did John buy?
Part B: To solve the equation, start by subtracting 18 from both sides to isolate the variable:
6x + 18 - 18 = 72 - 18
6x = 54
Next, divide both sides by 6 to solve for x:
6x/6 = 54/6
x = 9
Therefore, the value of x is 9.
Part C: In this equation, the value of the variable x represents the number of items John purchased.