Question

How would I find the answer to part B of the question?

Answer 1

Given the function of the height of the Elevator A:

`A(t)=80-4t`

And the function of the height of Elevator B:

`B(t)=5.2t+20`

You need to make:

`\begin{gathered} A(t)=45 \\ B(t)=45 \end{gathered}`

Substitute those values into the corresponding function and then solve for "t", in order to find when each elevator is at a height of 45 meters above the ground:

- For Elevator A, you get:

`45=80-4t`
`\begin{gathered} 45-80=-4t \\ \\ (-35)/(-4)=t \\ \\ t=8.75 \end{gathered}`

- For Elevator B:

`45=5.2t+20`
`\begin{gathered} 45-20=5.2t \\ \\ (25)/(5.2)=t \\ \\ t\approx4.81 \end{gathered}`

Hence, the answer is:

- For Elevator A:

`t=8.75`

- For Elevator B:

`t\approx4.81`