Question

Thanks!

Answer 1

we have to apply this formula:
\[\Large \frac{{f\left( 7 \right) - f\left( 4 \right)}}{{7 - 4}}\]

Answer 2

\[\frac{ f(3) }{ 3}\]
So it would be?

Answer 3

no, you have to substitute the expression of your function, like below:
\[\large \begin{gathered}
\frac{{f\left( 7 \right) - f\left( 4 \right)}}{{7 - 4}} = \hfill \\
\hfill \\
= \frac{{\left( {2 \times {7^2} - 16 \times 7 + 57} \right) - \left( {2 \times {4^2} - 16 \times 4 + 57} \right)}}{3} \hfill \\
\end{gathered} \]

Answer 4

Would the average rate of change be 6?

Answer 5

So I had to plug in 4 and 4 into the original equation, then subtract them from each other and divide it by 3?

Answer 6

I meant plug in 7 and 4

Answer 7

you have to plug in 7 and 4, so, the next step is:
\[\large \begin{gathered}
\frac{{f\left( 7 \right) - f\left( 4 \right)}}{{7 - 4}} = \hfill \\
\hfill \\
= \frac{{\left( {2 \times {7^2} - 16 \times 7 + 57} \right) - \left( {2 \times {4^2} - 16 \times 4 + 57} \right)}}{3} = \hfill \\
\hfill \\
= \frac{{ - 14 + 32}}{3} = ...? \hfill \\
\end{gathered} \]

Answer 8

\[\frac{ 18 }{ 3}\]
Then simplified to 6?

Answer 9

that's right!

Answer 10

Thank you!!

Answer 11

:)