To find Ms. Tanaka's earnings for selling 12 televisions, we can evaluate the expression \(2,500 + 100t\) with \(t = 12\).
Substituting \(t = 12\):
\[ \text{Earnings} = 2,500 + 100(12) \]
Calculating the multiplication:
\[ 100(12) = 1,200 \]
Now, add this to the base salary:
\[ \text{Earnings} = 2,500 + 1,200 = 3,700 \]
So, Ms. Tanaka will earn $3,700 for selling 12 televisions this month.