Question

I got it wrong but SOS

Answer 1

well, the wording is

"the yards from their goal line as a function of the number of plays"

the number of plays is the independent variable, meaning the dependent variable is the number of yards, hmmm so they're about to start their play on the 5-yard line, meaning the number of plays at this point is 0, zilch, then they move on each 3 plays by 10 yards, so let's make a table

`\begin{array}{ccll} Plays&Yards\\ \cline{1-2} 0&5\\ 3&\underset{5+10}{15} \end{array}\hspace{5em} (\stackrel{x_1}{0}~,~\stackrel{y_1}{5})\qquad (\stackrel{x_2}{3}~,~\stackrel{y_2}{15}) \\\\\\ \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{15}-\stackrel{y1}{5}}}{\underset{run} {\underset{x_2}{3}-\underset{x_1}{0}}} \implies \cfrac{10 }{ 3 }`

`\begin{array} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_1}{5}=\stackrel{m}{ \cfrac{10 }{ 3 }}(x-\stackrel{x_1}{0})\implies y-5=\cfrac{10}{3}x`

oddly enough, looks like yours :)