Warm up 20 Find the slope: 1.) (4,0) (5,7) 2.) (-3,3) (-3, -2) 3.) (3/4, ½) ( 1/4, -1/2) 4.)(-3,4) (2,4)

7.5 Equations and Slope Objective goal: 1.) To find slope and y-inercept of a line from an equation 2.)To graph lines using the slope-intercept equation

Slope-intercept equation y = mx + b y-intercept

To find the slope (m) and y-intercept of an equation: Write the equation in the y-intercept form Solve for “y” y = mx + b “m” is the slope “b” is the y-intercept

Find the slope and y-intercept of y = -5x + 6

Find the slope and y-intercept of 2y = 7x - 4

Find the slope and y-intercept of 2x + 3y = 6 3y = - 2x + 6 3 3 3

Find the slope and y-intercept of -7x - 5y = 25 -5y = 7x + 25 -5 -5 -5

Going the other direction… Given slope and the y intercept write your equation in slope-intercept form (y=mx+b) 1.) m=3, b=-2 Y=3x+-2 2.) m=0, b= -5 Y= -5 3.) m=1/2, b= 1 Y=1/2 x +1

Steps To Graph Using y=mx+b Slope Intercept From: 1.) Solve for y so your equation is in y=mx+b format 2.) Plot your b (y-intercept) on the y-axis 3.) From your y intercept use your slope to go up and over depending on the rise over run of your slope and plot your 2nd point.(If your slope is – you go down and to the right, if it is + you go up and to the right) 4.) Now that you have 2 points draw your line

Using y-intercept and slope, graph:

Using y-intercept and slope, graph:

Using y-intercept and slope, graph:

In closing…. We now have three methods to graph linear equations: 1.) 7.2 making a table and plotting three points 2.) 7.3 finding the x and y intercepts and plot two points 3.) 7.5 Putting the equation in slope intercept form and graphing the y intercept then use the slope to find the second point

Assignment Page 326 20-50 (even) on graph paper