To evaluate Ms. Tanaka's earnings for selling 12 televisions, we can use the formula given:
\[ \text{Earnings} = 2,500 + 100t \]
Substituting \( t = 12 \):
\[ \text{Earnings} = 2,500 + 100(12) \] \[ \text{Earnings} = 2,500 + 1,200 \] \[ \text{Earnings} = 3,700 \]
Thus, Ms. Tanaka will earn $3,700 for selling 12 televisions this month.