Question

Please Help, I will give out medal and fan rewards!

Answer 1

if you notice the table
as "t" increases, "d" increase

that is, for every passing month, you own $25 more

that means is a linear equation or a direct variation
as "x" increases, so does "y"

so using the table given, find the slope and thus get the equation for it \(\bf \begin{array}{ccllll}
t&d
\\\hline\\
1&25\\
{\color{red}{ 2}}&{\color{blue}{ 50}}\\
3&75\\
{\color{red}{ 4}}&{\color{blue}{ 100}}
\end{array}\\
\begin{array}{lllll}
&t_1&d_1&t_2&d_2\\
&({\color{red}{ 2}}\quad ,&{\color{blue}{ 50}})\quad &({\color{red}{ 4}}\quad ,&{\color{blue}{ 100}})
\end{array}
\\\quad \\

slope = {\color{green}{ m}}= \cfrac{rise}{run} \implies \cfrac{{\color{blue}{ d_2}}-{\color{blue}{ d_1}}}{{\color{red}{ t_2}}-{\color{red}{ t_1}}}
\\ \quad \\

d-{\color{blue}{ d_1}}={\color{green}{ m}}(t-{\color{red}{ t_1}})\qquad \textit{plug in the values and solve for "y"}\\
\qquad \uparrow\\
\textit{point-slope form}\)