To find the equation of this line, we need to pick 2 points from the graph:
[tex]\begin{gathered} (x_1,y_1)=(10,60) \\ (x_2,y_2)=(20,50) \end{gathered}[/tex]
Now, we can use the extended point-slope form of a line to figure the equation of the line shown. The form is given as:
[tex]y-y_1=\frac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]
Let's plug in the 2 points we have taken, re-arrange, and find the equation:
[tex]\begin{gathered} y-y_1=\frac{y_2-y_1}{x_2-x_1}(x-x_1) \\ y-60=\frac{50-60}{20-10}(x-10) \\ y-60=\frac{-10}{10}(x-10) \\ y-60=-1(x-10) \\ y-60=-x+10 \\ y=-x+10+60 \\ y=-x+70 \end{gathered}[/tex]
We don't have this exact equation, but the closest is Equation B.
(this discrepancy might be due to the point we chose, they can be a little off from the grid).
Correct Answer
B
