# 4 5 Graphing Linear Equations fguilbert Find the

4. 5 Graphing Linear Equations fguilbert

Find the slope between points (-1, -1) and (2, 3) y 2 - y 1 3 -- 1 x 2 - x 1 2 --1 The slope is 4/3. Up 4, right 3. fguilbert

Slope is change in y change in x Count to find slope. up 9 = 3 right 3 fguilbert

To graph a line using the slope and the y-intercept Slope-Intercept Equation of a line y = mx + b The slope of the line is m. The y-intercept is b. fguilbert

These equations are written in slope-intercept form. Y = mx + b y = 2 x – 3 Slope = 2 y-intercept = -3 y=-x+2 m = -1 fguilbert b=2

Graph y = 2 x – 3 y = mx + b b = -3 fguilbert

Graph y = 2 x – 3 b = -3 m=2 Begin at b = -3. Move up 2 units and then right 1 unit. Draw a line through the points. fguilbert

Graph Y = - x + 2 m= -1 b= 2 Start at b ( on the y axis). Use the slope to move to the next point. fguilbert

Y=-x+2 m = - 1 = -1 1 Start at 2 Go down 1 then right 1. m= -1 b=2 Does this look like a negative slope? fguilbert

y = -3 Is this y = mx + b ? y=0 x -3 b= -3 fguilbert

y = -3 y = 0 X -3 b = -3 m=0 fguilbert

Graph x= 3 Does this look like y = mx + b x y X= 3 3 0 no matter 4 3 1 what. 53 2 fguilbert

Graph x = 3 When x=# draw a vertical line through the number. fguilbert

y = mx + b To write an equation y = 4 x + 4 for a line. need m need b b=4 m=4 =4 1 fguilbert

Find theyequation. = mx + b y = -1/3 x - 2 b = -2 1 m= -3 fguilbert

for horizontal lines b=2 m=0 y = mx + b y=0 x +2 y= 2 fguilbert shortcut y=# y=2

vertical lines b = ? ? ? m is undefined cannot use y = mx +b fguilbert

Effort and courage are not enough without purpose and direction. fguilbert

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