Answer:
106
Step-by-step explanation:
Substitute x = 3 into f(x) and evaluate , that is
f(3)
= 10(3)² + 6(3) - 2 = 10(9) + 18 - 2 = 90 + 18 - 2 = 106
<em><u>45(x)-20 </u></em>
x=hours
7 hours
x=7
<em><u>45(7)-20 =295</u></em>
