To find out how much Miss Jenkins will earn for selling 12 televisions, we can substitute \( t = 12 \) into the equation \( 2,500 + 100t \).
Using the formula:
\[ \text{Earnings} = 2,500 + 100t \]
Substituting \( t = 12 \):
\[ \text{Earnings} = 2,500 + 100(12) \]
Calculating \( 100 \times 12 \):
\[ 100 \times 12 = 1,200 \]
Now, substitute this value back into the earnings equation:
\[ \text{Earnings} = 2,500 + 1,200 = 3,700 \]
Thus, Miss Jenkins will earn $3,700 for selling 12 televisions this month.