Slope-intercept form: y = mx + b
[m is the slope, b is the y-intercept or the y value when x = 0 ---> (0, y) or the point where the line crosses through the y-axis]
To find the slope(m), use the slope formula:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex] And plug in the two points
(1, 2) = (x₁, y₁)
(2, 3) = (x₂, y₂)
[lines go from left to right, so the point furthest to the left is the 1st point]
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
[tex]m=\frac{3-2}{2-1}[/tex]
[tex]m=\frac{1}{1}[/tex]
m = 1 Now that you found the slope, plug it into the equation
y = mx + b
y = 1x + b or y = x + b To find b, plug in one of the points into the equation (doesn't matter which point, I will use (1, 2))
2 = (1) + b Subtract 1 on both sides to get b by itself
2 - 1 = 1 - 1 + b
1 = b
y = x + 1
