x = 100, solve for x. 2.Given the data below, what is the probability that a person will buy a bicycle rather than a scooter. 3.x – 30 = -50, solve for x 4.Round the given number to the hundredths place, Round the given number to the ones place, Person APerson BPer so n C Pers on D Person E Scooterx xx Bicycle x x

Graphing Activity Get into groups of 2-3 students. Each group will get a starting point and a slope Your task is to find the next point in your line Then check your point by finding the slope between the starting point and your point

Standard Form x- and y-intercepts November 28/29, 2011

What is a Linear Equation? In a graph, Linear equations will be a line In a table, Linear equations will have an arithmetic pattern In an equation, Linear equations can be written as slope-intercept form, y = mx + b, and standard form, Ax + By = C

Standard Form To be a linear equation, an equation must be able to be written in the form Ax + By = C This is called Standard Form A, B and C are always integers (no fractions) A must be positive Is this in Standard Form? 3x + 5y = 12 1/2x – y = 12 -2x + 5y = 30

How to change an equation to Standard Form Write ⅔x = –6y + 1 in standard form. Identify A, B, and C. ⅔x = –6y + 1Original equation + 6y +6y___Add 6y to each side. ⅔x + 6y = 1 3(⅔x + 6y = 1) Multiply each side by 3 2x + 18y = 3 So, A = 2, B = 18, and C = 3.

Example 2 Put 2 + 5y = –x in Standard form and identify A, B and C y = –x Original equation 2 + 5y = –x Add x to each side. + x + x 2 + 5y + x = 0Subtract 2 from each side y + x = 0 – 2 – 2 x + 5y = –2Simplify. A = 1, B = 5, and C = –2.

Now You Try Can this be written in Standard Form? If yes, change to Standard Form. y = 2x + 5 7x = 4y – 6 y = x² + 6 ¾x + ½y = 12

Practice Work on problems 1-9 You have 15 minutes.

Finding x- and y-intercepts x-intercept – where a line crosses the x-axis – when y = 0 – (x, 0) y-intercept – where a line crosses the y-axis – when x = 0 – (0, y)

Finding the x-intercepts and y- intercepts (continued) Which is the intercepts? A x-intercept is 0; y-intercept is 6. B x-intercept is –3; y-intercept is 0. C x-intercept is –3; y-intercept 6. D x-intercept is 6; y-intercept is –3. y x O

Graphing using x-intercepts and y- intercepts To find the x-intercept, let y = 0 5x – y = 10Original Replace y with 0. 5x – 0 = 10Simplify. 5x = 10 Divide each side by 5. x = 2 x-intercept is (2, 0) To find the y-intercept, let x = 0. 5x – y = 10Original Replace x with 0. 5(0) – y = 10Simplify. –y = 10 Multiply each side by –1. y = –10 y-intercept is (0, -10) Graph 5x – y = 10 using the x- and y-intercepts.

Finding x- and y-intercepts Now you try y – 3x = -1 5x + 3y = 15 x + 4y = -8

Finding x- and y-intercepts Now you try

Practice Work on problems You have 15 minutes