To find the equation of the line passing through the points (1, 8) and (-2, -1), we first need to find the slope of the line. The slope (m) can be found using the formula:
m = (y2 - y1) / (x2 - x1)
Substitute the coordinates of the points into the formula:
m = (-1 - 8) / (-2 - 1)
m = -9 / -3
m = 3
Now that we have the slope, we can use the point-slope form of the equation of a line to find the equation in slope-intercept form. The point-slope form is:
y - y1 = m(x - x1)
Choose one of the given points to substitute into the equation. Let's use (1, 8):
y - 8 = 3(x - 1)
Now, simplify the equation:
y - 8 = 3x - 3
y = 3x - 3 + 8
y = 3x + 5
Therefore, the equation of the line passing through the points (1, 8) and (-2, -1) in slope-intercept form is y = 3x + 5.
