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:
And plug in the two points
(2, 1) = (x₁, y₁)
(5, -8) = (x₂, y₂)
m = -3 Now that you know m = -3, substitute/plug it into the equation
y = mx + b
y = -3x + b To find b, plug in either of the two points into the equation, it doesn't matter which. I will use (2, 1)
1 = -3(2) + b
1 = -6 + b Add 6 on both sides to get "b" by itself
7 = b
y = -3x + 7