Question

Suppose that the function f(x)=7x-3 represents the number of the people in a crosswalk for x seconds after the “walk” sign appears in a busy intersection. How many people are in the crosswalk 8 seconds after the “walk” sign appears?

Answer 1

Solution

We are given the function

$f(x)=7x-3$

We want to find f(x) at x = 8 or f(8)

Put x = 8

$\begin{gathered} f(x)=7x-3 \\ f(8)=7(8)-3 \\ f(8)=56-3 \\ f(8)=53 \end{gathered}$

There are 53 people on the crosswalk after 8 seconds after the walk sign appear