Warm Up… Solve each equation for y. y – 5 = 4x (2) y + 2x = 7 (3) 2y + 6 = -8x Calculate the slope given the two points. (4) (-4, 4) and (2, -5) (5) (0, -1) and (1, -6)

#6.2 - Graphing Linear Equations In Slope-Intercept Form Objective: SWBAT graph linear equations

A linear equation graph will always create a line. Linear equations are in the form y = mx + b or can be rewritten into the form y = mx + b. In this section, instead of making a table, evaluating y for each x, plotting the points and making a line, we will use The Slope-Intercept Form of the equation to graph the line.

Notice that these equations are all solved for y. These equations are all in Slope-Intercept Form: Notice that these equations are all solved for y.

y = mx + b Formula for Slope – Intercept Form ‘b’ is the y-intercept (the point where the graph crosses the y – axis) ‘m’ is the slope

Just by looking at an equation in this form, we can draw the line (no tables). The constant is the y-intercept. The coefficient is the slope. Constant = 1, y-intercept = 1. Coefficient = 2, slope = 2. Constant = -4, y-intercept = -4. Coefficient = -1, slope = -1. Constant = -2, y-intercept = -2. Coefficient = 3/2, slope = 3/2.

right 1 up 2 right 1 up 2

down 1 down 1 right 1 right 1

right 2 up 3 right 2 up 3

y = x

y = -3 x = 2

Sometimes we must solve the equation for y before we can graph it. The constant, b = 3 is the y-intercept. The coefficient, m = -2 is the slope.