Identifying Slope and Y-Intercept from Graph or Equation

1. y = mx + b
The Equation of a Line!

2. Lines that we graph have two important values
that we must know:
SLOPE
and
Y-INTERCEPT

3.  Slope is how fast a line
RISES or FALLS.
 The formula is:
Change in y y2
– y1
Change in x x2
– x1
 The y-intercept is the
point where a line
touches the y-axis
(vertical axis).

4. (6, 8)
(2, 2)
(0, -3)
y – intercept = -3
slope = 8 – 2 6 3
6 – 2 4 2
Equation: y = (3/2)x - 3

5. y = mx + b
m = slope
b = y-intercept
1) y = -3x + 6 2) 2x + 3y = -12
Slope = -3 3y = -2x - 12
Y-intercept = 6 y = -(2/3)x – 4
Slope = -(2/3)
Y-intercept = -4

6. y = (1/2)x - 5 4x – 2y = 8
Answers are on the next page…but don’t look yet!

7. 1. Slope = ½, y-intercept = -5
2. Slope = 2, y-intercept = -4