Slope-intercept form is mx + b = y where m is the slope and b is the y intercept. We know m, which is 3, which makes the equation 3x + b = y, so we need to find b. This is where the point comes in. We can fill in the x and y in the slope-intercept form an equation to solve for b.
3(9) + b = -4
27 + b = -4
b = -31
Therefore, the equation with the slope of 3 that passes through point (9, -4) is:
3x - 31 = y.
