Warm Up #20 1.) Graph 5x + 7y =35 2.) Graph 2x -3

Graph 5x + 7y =35 X -values Y- values (X, Y) 7 -5/7(7)+5 (7, 0) (7, 0) -5/7(0)+5 5 (0,5) -7 -5/7(-7)+5 10 (-7, 10) Solve for “y” 7y = -5x +35 Y = -5/7 x + 5

Find 3 points using the table, and graph the line of the equation Find 3 points using the table, and graph the line of the equation. y = 2x - 3 1 -1 -3 -5 -1 This is a review, scaffolding slide. Have each student graph the equation at their desk. W#alk around and check.

7.3 Linear Equations and Their Graphs Objective: To graph linear equations using the x and y intercepts To graph horizontal and vertical lines

Linear Equations (Graphs are straight lines) Equation is linear only if the each variable has an exponent of “1”. (exponent in denominator is not linear) Products of variables not linear, ie (x)(y) y – 3x = -7 y = 2x + 1 y = x2 + 1 Teach and discuss the 3 bullets. The next click will display the yellow example of bullet 2. The next click will display one of the green examples. Ask class to decide if linear or not, then call on one “random” STUDENT TO ANSWER AND EXPLAIN WHY IF NOT LINEAR. 5y = 14 xy = 2

y X x - intercept y - intercept Definitions. Instruct student to add to notebook. y - intercept

Graphing using Intercepts Let x=0 and determine the y-intercept. Let y=0 and determine the x-intercept Plot both points. Connect them with a line. More for notebook

Graph 4x + 3y = 12 using intercepts Find x-intercept 4x + 3(0) = 12 Find y-intercept 4(0) + 3y = 12 4x = 12 3y = 12 x = 3 y = 4 Teach and demonstrate the concept.

Graph 2x + 3y = 12 using intercepts 6 This slide introduces the X-Y intercept table. Teach and demonstrate the steps.

Graph 3x + 5y = 15 using intercepts 5 Have students make an intercept table and graph the equation on each of the next 6 slides. The steps are shown for students still needing to see it. I provide graph paper with 6 graphs per front and back.

Graph 5x - 2y = 10 using intercepts 2

Graph 2y = 3x - 6 using intercepts 2 This is the first problem not in slope intercept form and will catch many. Teach.

Horizontal and Vertical Lines The graph of y= # is HORIZONTAL The graph x =# is VERTICAL

Graph 4y = 16 using 3-points x y 3 6

Graph 3x = 18 using 3-points x y 3 - 4

Differences between graphing by using a table and graphing by finding the x and y intercepts When graphing by a table you need to solve for y (Slope Intercept Form y=mx+b) When graphing by finding the x and y intercepts you do not have to solve for y (Standard Form Ax +By =C)

Assignment Page 316 16 – 40 (even) (use graph paper)