To find out how much Ms. Tanaka will earn for selling 12 televisions, we will plug \( t = 12 \) into the formula \( 2,500 + 100t \).
Substituting \( t \):
\[ 2,500 + 100(12) \]
Calculating \( 100(12) \):
\[ 100 \times 12 = 1,200 \]
Now, adding that to the base salary:
\[ 2,500 + 1,200 = 3,700 \]
Therefore, Ms. Tanaka will earn $3,700 for selling 12 televisions this month.