WarmUp 1202 Write the equation of a line

Warm-Up 12/02 Write the equation of a line in slope intercept form that has a slope of -3 and a y-intercept of 2. 2. Write the equation of a line in slope intercept form that has a slope of 2 and a y-intercept of -5 Find the slope and y-intercept of the following: 1.

Unit 4 B Day 1 Standard Form of an Equation

Standard Form of an Equation Write the equation for STANDARD FORM: Ax + By = C A, B, and C must be whole numbers and A and B are both not zero

Change to Standard Form � Examples of Standard Form � 3 x + 5 y = 3 �-2 x + y = 7 � 2 x − y =6 � Equations Non-Examples �x = 6 − y �y = 2 x + 7 � 2 y = 4 x +2

When is Standard Form useful? � When you want to graph the line � When you want to know the y-intercept of the line � When you want to know the x-intercept � Writing equations. y-intercept – the y value of the point where the line crosses the y-axis x-intercept – the x value of the point where the line crosses the x-axis

Examples Change each equation into Standard Form: 1. 2 y = 4 x – 6 2. x + 7 = ½y 3. x = -3 y - 8

Try on your own: 4. 9 x + 4 = -y 5. y = -5 x + 1 6. ¼x – ¾y = -1

Find the y-intercept The y-intercept always occurs when x=___. To find the y-intercept of a line when the equation is in Ax + By = C, plug 0 into x in the equation and solve for the y value. This becomes the ordered pair for the y-intercept. (0, b)

Find the y-intercept 1. 2 x – y = -6 2. -2 x + 4 y = 12

On your own: 3. 7 x – 14 y = -56 4. -3 x + 2 y = 6

Find the x-intercept The x-intercept always occurs when y=___. To find the x-intercept of a line when the equation is in Ax + By = C, plug 0 into y in the equation and solve for the x value. This becomes the ordered pair for the x-intercept. (x, 0)

Find the x-intercept 1. 2 x – y = -6 2. -2 x + 4 y = 12

On your own: 3. 7 x – 14 y = -56 4. -3 x + 2 y = 6

Classwork WS

Classwork 1. 2. 3. 4. 5. 6.