Question

Line MN passes through points M(4, 3) and N(7, 12). If the equation of the line is written in slope-intercept form, y = mx + b, what is the value of b?

Answer 1

-9

Explanation:

Answer 2

b = -9

Explanation:

As we go from M(4, 3) to N(7, 12), x increases by 3 and y increases by 9. Thus, the slope of the line segment connecting these two points is m = rise / run = m = 9/3, or just m = 3.

Subbing the coordinates of M into y = mx + b, we get:

3 = 3(4) + b, or 3 = 12 + b, so that b = -9.