Complete the equation of the line through (2, 1) and (5 −8) answers

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