4-2 Writing equations in Slope Intercept

Form

A Short ReviewWrite an equation of the line with the given slope and y-intercept. slope: 3, y-intercept: –1

Write an equation of the line with the given slope and y-intercept.

Graph the equation 2y – 3x = 6? Graph the equation y = 3x + 1?

A Short ReviewWhich of the following equations has a slope of ?

A. 3y = –2x + 9

B. 3y = x – 12

C. –3y = x – 12

D. 4y = –3x + 8

EQ:

Why is math used to model real-world situations?

I will be able to…….Write and graph linear equations in slope-intercept from.…Model real-world data with equations in slope-intercept formWrite an equation of a line in slope-intercept form given the slope and one point.Write an equation of a line in slope-intercept form given two points.

1

3

How does this apply to me?

What two points would be on the graph of the data?

How could you find the slope of the line that would model the data?

How could you use the equation that models this situation to predict the zoo attendance in any given year?

Writing an equation given the slope and a point.

Vocabulary: linear extrapolation Write an equation of a line that passes through (1, 4) and has a slope of –3.

Write an equation of a line that

passes through (2, –3) with a

slope of

Writing an equation given two points.

Write the equation of the line that passes through (–3, –4) and (–2, –8).

Write the equation of the line that passes through (6, –2) and (3, 4).

Writing an equation given two points.Write the equation of the line that passes through the points (–2, –1) and (3, 14).A. The table of ordered pairs shows

the coordinates of two points on the graph of a line. Write an equation that describes the line?

Real World ProblemECONOMY During one year, Malik’s cost for self-serve regular gasoline was $3.20 on the first of June and $3.42 on the first of July. Write a linear equation to predict Malik’s cost of gasoline the first of any month during the year, using 1 to represent January.What do we know? (Fill in the chart)

More real world problems…The cost of a textbook that Mrs. Lambert uses in her class was $57.65 in 2005. She ordered more books in 2008 and the price increased to $68.15. Write a linear equation to estimate the cost of a textbook in any year since 2005. Let x represent years since 2005.

Mrs. Lambert needs to replace an average of 5 textbooks each year. Use the prediction equation y = 3.5x + 57.65, where x is the years since 2005 and y is the cost of a textbook, to determine the cost of replacing 5 textbooks in 2009.

Things to remember: Things to remember: • Homework• Project due Monday• Get your Mixture In or I will be calling

home this weekend.• Continue to organize your notebook

Dates to remember :

Project due October 28, 2013Exam Tuesday, November 5, 2013