From the graph, the coordinates given are
[tex]\begin{gathered} (x_1,y_1)\Rightarrow(0,50) \\ (x_2,y_2)\Rightarrow(3,350) \end{gathered}[/tex]
The general equation of a line in slope-intercept form is
[tex]\begin{gathered} y=mx+c \\ \text{where,} \\ m=\text{slope} \\ c=y-\text{intercept} \end{gathered}[/tex]
The formula used to calculate the equation of a line when two points (x1,y1) and (x2,y2) are given is
[tex]\frac{y-y_1}{x-x_1}=\frac{y_2-y_1}{x_2-x_1}[/tex]
By substituting the values, we will have
[tex]\begin{gathered} \frac{y-y_1}{x-x_1}=\frac{y_2-y_1}{x_2-x_1} \\ \frac{y-50}{x-0}=\frac{350-50}{3-0} \\ \frac{y-50}{x}=\frac{300}{3} \\ \frac{y-50}{x}=100 \\ \text{cross multiply} \\ y-50=100x \\ y=100x+50 \end{gathered}[/tex]
Therefore,
The equation of the line is y = 100x + 50
By comparing coefficients,
The slope = 100 ( one hundred dollars balance per deposit)
The y-intercept = 50 ( fifty dollars)
