The general equation of a line is:
[tex]y=m\cdot x+b[/tex]
Where m is the slope of the line and b its the value of the y-intercept of the line.
Q) The question asks about the equation of a graphed line.
A) In order to find the equation of the line, we note that it passes through the points:
[tex]\begin{gathered} (x_1,y_1)=(0,-2) \\ (x_2,y_2)=(4,-1) \end{gathered}[/tex]
The first point give us the value of the y-intercept of the line (b), so the y-intercept is y = -2, and we have:
[tex]b=-2[/tex]
Now we must calculate the slope (m) of the line. In general the slope of a line is given by the following formula:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
Where (x1,y1) and (x2,y2) are the coordinates of two points of the line. Using the points of above and the last formula we find that:
[tex]m=\frac{y_2-y_1}{x_2-x_1}=\frac{-1-(-2)}{4-0}=\frac{2-1}{4}=\frac{1}{4}[/tex]
Answer
Using the values of m and b, and the general equation, we find that the equation of the line is:
[tex]y=m\cdot x+b=\frac{1}{4}x-2[/tex]
Or: y = 1/4 x - 2
So the correct option is option number 3.
