Warm Up… Solve each equation for y. (1)y – 5 = 4x (2) y + 2x = 7 (3) 2y + 6 = -8x Calculate the...

Warm Up…Solve each equation for y.

(1)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 EquationsIn 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.

These equations are all in Slope-Intercept Form:

Notice that these equations are all solved for y.

Formula for Slope – Intercept Form

• ‘b’ is the y-intercept (the point where the graph crosses the y – axis)

• ‘m’ is the slope

y = mx + b

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.

up 2

right 1 up 2

right 1

right 1down 1

right 1

down 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.