Final answer:
To determine how many miles Carmen jogged last week, the equation 0.5x + 3 = 12 can be used. By solving this equation, we find that Carmen jogged 18 miles last week.
Step-by-step explanation:
The student is asking for an equation to find out how many miles Carmen jogged last week, given that this week she jogged twelve miles which is three more than half as many miles as last week.
Let's denote the number of miles Carmen jogged last week as x. According to the problem, Carmen jogged half as many miles plus three this week. We can write this as an equation: 0.5x + 3 = 12.
To find the number of miles Carmen jogged last week (x), we need to solve for x by first subtracting 3 from both sides to isolate the term with x, and then dividing by 0.5:
- 0.5x + 3 - 3 = 12 - 3
- 0.5x = 9
- x = 9 / 0.5
- x = 18
Therefore, Carmen jogged 18 miles last week.