5-1 thru 5.3 review: students will be able to write an equation of a line in slope intercept form....

5-1 thru 5.3 review: Students will be able to write an equation of a line in slope intercept form.

WARM-UP

ANSWER

ANSWER

1. (1, 4), (6, –1) Y = -x + 5

2. (-1, -2), (2, 7)

Write an equation in slope intercept form of the line that passes through the given points.

ChallengeYou have a job that pays by the hour. On Monday, you worked 5 hours and earned $30. On Tuesday, you worked 3 hours and earned $18.1. Let x represent the number of hours worked and let

y represent the amount earned. Write two ordered pairs.

2. Plot the two points given by the ordered pairs. Draw a line through the points.

3. Find the slope and the y-intercept of the line.4. Write the equation of this line.

Y = 3x + 1


WARM-UPChallenge Answers

You have a job that pays by the hour. On Monday, you worked 5 hours and earned $30. On Tuesday, you worked 3 hours and earned $18.

1. Let x represent the number of hours worked and let y represent the amount earned. Write two ordered pairs.(5, 30) (3, 18)

2. Plot the two points given by the ordered pairs. Draw a line through the points.

3. Find the slope and the y-intercept of the line. 30-18 / 5-3 = 12/2 = 6 y-int= 04. Write the equation of this line.

Y = 6x + 0, y = 6x

OBJECTIVE: Students will be able to write an

equation of a line in slope intercept form.

Quiz on 5.1 – 5.3 Thursday

5.4 review on Friday

5.5 on Monday


REVIEW HOMEWORK


GROUPS Group A

Work with me to review 5.1 – 5.3

Group BTextbook: Page 289 – 290 # 40, 46, 48 - 57


ARE THESE IN SLOPE INTERCEPT FORM? y = 3x + 5 3 = 2x + b y = ½ x y = 8x + 8 y = 9 (3) + 9 4 = 5m + b y = 5x + 1.5 y = 3.5x + 89

Hint:

y = mx + b


SLOPE INTERCEPT FORM Goal: Write the equation in the form:

y = mx + b

To do this, you need to find the m and the b

m = slopeb = y-intercept

The y and x should stay as variables.

5-1 thru 5.3 review: Students will be able to write an equation of a line in slope intercept form.PARALLEL &

PERPENDICULAR LINES Parallel lines have the same slope.Example

y = ½ x + 3y = ½ x + 10

Perpendicular lines: Use the negative

reciprocal.

y = 3/5 x + 10y = -5/3 x + 15


SOLUTION

Write an equation of a parallel line

Write an equation of the line that passes through (–3, –5) and is parallel to the line y = 3x – 1.

STEP 1

Identify the slope. The graph of the given equation has a slope of 3. So, the parallel line through (–3, –5) has a slope of 3.

STEP 2

Find the y-intercept. Use the slope and the given point.


y = mx + b

–5 = 3(–3) + b

4 = b

Write slope-intercept form.

Substitute 3 for m, 3 for x, and 5 for y.

Solve for b.

STEP 3

Write an equation. Use y = mx + b.

y = 3x + 4 Substitute 3 for m and 4 for b.


1. Write an equation of the line that passes through

(–2, 11) and is parallel to the line y = –x + 5.

y = –x + 9ANSWER


SOLUTION

Write an equation of the line that passes through (4, –5) and is perpendicular to the line y = 2x + 3.

STEP 1

Identify the slope. The graph of the given equation has a slope of 2. Because the slopes of perpendicular lines are negative reciprocals, the slope of the perpendicular line through (4, –5) is .

12

–


STEP 2 Find the y-intercept. Use the slope and thegiven point.

Write slope-intercept form.

–5 = – (4) + b1

2Substitute – for m, 4 for x, and –5 for y.

12

y = mx + b

–3 = b Solve for b.

STEP 3 Write an equation.

y = mx + b Write slope-intercept form.

y = – x – 312 Substitute – for m and –3 for b.1

2


HOMEWORK Page 291 Quiz 1, 1-13

5-1 thru 5.3 review: students will be able to write an equation of a line in slope intercept form....

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