Let's define the variables in the problem:
- Let \( T \) be the number of bags Trisha bought.
- Each bag contains 12 clementines.
According to the problem:
- Sal brought 4 bags of clementines, so he brought \( 4 \times 12 = 48 \) clementines.
- Joe brought 6 bags of clementines, so he brought \( 6 \times 12 = 72 \) clementines.
- The total number of clementines is 180.
We can write an equation based on the total number of clementines:
\[ 48 + 72 + 12T = 180 \]
Now, we can simplify the left side:
\[ 120 + 12T = 180 \]
Now, subtract 120 from both sides to isolate the term with \( T \):
\[ 12T = 180 - 120 \] \[ 12T = 60 \]
Now, divide both sides by 12 to solve for \( T \):
\[ T = \frac{60}{12} = 5 \]
So, Trisha bought 5 bags of clementines.