Answer:
D. 160
Explanation:
This question asks us to find f(8). Essentially, this asks us to find out what y is when x is equal to 8. In terms of this problem, how many minutes does he practice after 8 days.
We are given the equation:
y=20x
We want to find f(8). Therefore, we must substitute 8 in for x.
y=20(8)
Multiply 20 and 8
y=160
Therefore, f(8) is 160 and D is the correct answer. This means that after 8 days, Emilio practices for 160 minutes.