To find out how much Ms. Tanaka will earn for selling 12 televisions, we can use the formula:
\[ \text{Total Earnings} = 2,500 + 100t \]
where \( t \) is the number of televisions sold. Given \( t = 12 \):
\[ \text{Total Earnings} = 2,500 + 100(12) \]
Calculating the sales commission:
\[ 100(12) = 1,200 \]
Now, substituting this value back into the equation for total earnings:
\[ \text{Total Earnings} = 2,500 + 1,200 = 3,700 \]
Therefore, Ms. Tanaka will earn $3,700 for selling 12 televisions this month.