Equation of a line
The equation of a line in the slope-intercept form is:
y = mx + b
Where m is the slope of the line and b is the y-intercept.
Suppose we know the line passes through points A(x1,y1) and B(x2,y2). The slope can be calculated with the equation:
[tex]\displaystyle m=\frac{y_2-y_1}{x_2-x_1}[/tex]
We need to identify two clear points through which the line passes. We select the points (0,-3) and (4,5). Calculate the slope:
[tex]\displaystyle m=\frac{5+3}{4-0}=\frac{8}{4}=2[/tex]
1. The slope is m=2
The y-intercept of the line is the y-coordinate of the point where the line crosses the y-axis.
2. We can see the line crosses the y-axis at the point (0,-3), thus the y-intercept is b=-3.
3. The equation of the line is written as follows:
y = 2x - 3
