ALGEBRA CHAPTER 5 Linear equations and inequalities

Warm up – Tuesday (copy homework first!!) 1)What is the complement and supplement of a 79 degree angle? 2)Find four consecutive integers whose sum in 98. 3)If the width of a rectangle is 2 more than four times the length and the perimeter is 84 meters. What is the length and the width.

NOTES: 5.1 AND (should be review) 5.2 – graphs of straight lines

5.2 – Notes (IMPORTANT VOCABULARY!) Linear equations - A graph that makes a straight line. Slope-intercept form of an equation: y = mx + b

What is slope? *the steepness of a line* (think ski slopes) Different types of slope: a) positive b) negative c) no slope

Graphing equations in y=mx + b form using a table: 1) y = 3x + 2 XY

Graphing equations in y=mx + b form using a table: 2) y = ½x – 4 XY

You try: 3) y = -3x + 5 XY

Review from yesterday: 1) y = -4x – 2 XY

Warm up – Wednesday (copy homework!) 1)Six times the sum of a number and 4 is equal to Four times a number and 8. 2)The length of the court that needs to be re-done is 14.3ft long by 9ft wide. If it cost $6 a square foot. How much will it cost to re- do the floor? 3)Complete the table for: y = 3x – 1. What is the slope? What is the y-intercept? Xy 0 1

Is this a solution to the equation? Plug in both variables and see if they two sides equal each other. If they are equal it is a solution, if they are not equal then it is not a solution. 1) y = -4x + 6 a(-3, -6) b (2, -2) c (-5, 26)

YOU TRY: Is this a solution to the equation? 1) y = 3x – 8 a(-2, -14) b (4, 6) c (-3, -17)

x and y intercepts: x intercept – plug zero in for the y value (#, 0) y intercept – plug zero in for the x value (0, #) 1) y = -4x ) y = ½x + 16

5.2 notes continued: Standard form of the equation: Ax + By = C ex. 3x + 4y = 12 **Change the equation into y=mx + b form.**

Solve for y and then graph each equation with at least three points: 1) 3x – 6y = 18 2) 2y – 8x = -14

Warm up – Thursday 1)Complete the table: y = ½x – 6 what is the y-intercept? what is the slope? 2)Is this a solution? a) y = -4x – 2; (2, 10)b) 3y = -4x – 9; (3, -7) 3) What are the x and y intercepts to: 2y = -3x – 12 (Hint – Plug in zeros) XY

Graph using slope and y-intercept: **remember must put the equation in y = mx+b form in order to use this method** Slope = Rise Run

Slope can be used in order to help graph the equation or create a table easier. Slope in a table: Slope in a graph:

XY

XY

Graph and make a table with the equation using slope and y-intercept. Must have three points on each line! 3) y = 3x – 2 slope = y intercept = XY

Homework check (close your book!) Tuesday night(last week) (pg. 104) 1) #10 2) #16 3) #18 Wednesday night(last week) (pg. 104) 4) #9 5) #15 6) # #17 Monday night (pg. 198 – 199_ 7) #4 8) #16 9) #22