Chapter 8.5, Problem 49PPS

To determine

To write: The expression in factored form and find the height of the arrow after 3 seconds.

Answer to Problem 49PPS

The factored form of the given model is $8t\left(9-2t\right)$

And the height of the arrow after 3 seconds is $72$ feet.

Explanation of Solution

Given:

The height in feet of an arrow is $72t-16t^2$ , where t is the time in seconds after the arrow is released.

Calculation:

The given model is $72t-16t^2$

Factored out the GCF

  $8t\left(9-2t\right)$

Substituting $t=3$ in the given model

  $\begin{array}{l}72\left(3\right)-16{\left(3\right)}^2\\ =216-144\\ =72\end{array}$

So, the factored form of the given model is $8t\left(9-2t\right)$

And the height of the arrow after 3 seconds is $72$ feet.