To calculate Ms. Tanaka's total earnings for selling 12 televisions, we can substitute \( t = 12 \) into the salary formula:
\[ \text{Total Earnings} = 2,500 + 100t \]
Substituting \( t \):
\[ \text{Total Earnings} = 2,500 + 100(12) \]
Now calculate \( 100(12) \):
\[ 100(12) = 1,200 \]
Now add this to the base salary:
\[ \text{Total Earnings} = 2,500 + 1,200 = 3,700 \]
So, Ms. Tanaka will earn $3,700 for selling 12 televisions this month.