To determine the last point graphed on the first piece of the piecewise function \(f(x) = 2.5x\) for the defined range \(0 \leq x \leq 20\), we evaluate the function at the upper limit of the interval, which is \(x = 20\).
Calculating \(f(20)\):
\[ f(20) = 2.5 \times 20 = 50 \]
Thus, the last point on the first piece of the function is \((20, 50)\).
The correct response is:
(20, 50)