This document explains how to write an equation in slope-intercept form (y=mx+b) given a point and slope. It shows that to find the b term, you take the y-value of the given point and substitute it and the x-value into the formula y=mx+b, then solve for b. Several examples are worked through, finding the equations for various lines with given points and slopes.

1. Slope Intercept Form Using a point and slope

2. Slope Intercept form y = mx + b Find slope-int form for (3,2) & m=2

3. Remember y=mx+b in its final form : y & x are left as variables #’s replace m & b

4. To find b We know m, but we don’t know b We have a point We need to use that point and the m to find the missing b to write the final form of y=mx+b

5. (3,2) m=2 y=mx+b 2=2(3) + b 2=6 +b -4=b y=2x - 4

6. Ex: 1 (-2,3) m=1/2 y=mx+b 3=(1/2)(-2) + b 3=-1 +b 4=b y=1/2x + 4

7. Ex: 2 (9,3) m=-2 y=mx+b 3=(-2)(9) + b 3=-18 +b 21=b y=-2x + 21

8. Ex: 3 (1,-3) m=1/3 y=mx+b -3=(1/3)(1) + b -3=1/3 +b -10/3=b y=1/3x – 10/3