Download File

Warm Up
• Write down objective and homework in agenda
• Lay out homework (None)
• Homework (6-3, #21-36)
• Slope project due Friday, Nov. 8! (Quiz Grade!!!)
Warm Up
• Find the slope of the line that contains each
pair of points.
– 1) (3, 6), (1, 12)
– 2) (9, -2), (-6, -2)
• Complete each ordered pair so that it is a
solution of the equation y = -2x + 3
– 3) (2, ?)
– 4) (0, ?)
– 5) (?, 11)
Warm Up-Answers
• Find the slope of the line that contains each
pair of points.
– 1) (3, 6), (1, 12) y = -3x + 15
– 2) (9, -2), (-6, -2) y = -2
• Complete each ordered pair so that it is a
solution of the equation y = -2x + 3
– 3) (2, -1)
– 4) (0, 3)
– 5) (-4, 11)
STANDARD FORM!
• What does standard form of an equation look
like?!
Standard Form
• Ax + By = C
• Be sure you move all variables to the left side
• Get rid of any fractions
• Always place x first
When given two points, always find
slope-intercept form first!
Find the equation for the line containing the
points (4, 2) and (3, 6).
1. Find the slope using the formula.
m=2–6
4–3
m = -4
(4, 2) and (3, 6)
m = -4
2. Find the y-intercept.
y = mx + b
2 = -4 • 4 + b
2 = -16 + b
18 = b
(4, 2) and (3, 6)
m = -4 b = 18
3. Write equation in y = mx + b.
y = -4x + 18
4. Convert to Ax + By = C.
4x + y = 18
Write your equation in STANDARD
1
form given m =  3 and b = 2.
First, write in slope-intercept form:
1
y=  x+2
3
Now, write it in standard form.
(Ax + By = C where A, B, and C are integers).
Clear the fractions - multiply everything by 3.
1
(3)y = (3)( x) + (3)2
3
3y = -x + 6
Get the variables on the same side.
x + 3y = 6
Write the standard form for a line passing
through the points (-1, -3) and (-4, 6).
Find slope…
9
6  (3)

 3
m
4  (1) 3
Find y-intercept. I’m choosing the point (-4, 6).
6 = -3(-4) + b
6 = 12 + b
-6 = b
Slope-intercept form: y = -3x - 6
Standard form: 3x + y = -6
Example
You Try!
• Y = 1/2x + 7
• -x + 2y = 14
• x – 2y = -14
• (9, 3), (19, −17)
• 2x + y = 21
• -2x – y = -21
Turn 4 into standard form!
Word Problems in Standard Form
• The math club is selling 300 pounds of
chocolate to raise money for new calculators.
The chocolate is sold in 2 lb boxes and 5 lb
boxes.
• Write an equation to find the number of each
type of box the club should sell.
• 2x + 5y = 300
Word Problems in Standard Form
• 2x + 5y = 300
• Graph the equation & find two different
combinations
Word Problems in Standard Form
• Student council is sponsoring a carnival to
raise money. Tickets are $8 for adults & $5 for
students. The student council wants to raise
$500.
• Write an equation to find the number of each
ticket they should sell
• Graph the equation & find two possible
solutions
• 8x + 5y = 500
You Try!
• You must spend $60 on dessert for a party.
Cupcakes are $3 a piece and mini cheesecakes
are $4. Write an equation to relate to the
number of each dessert you could use
Graphing in Standard Form
• Switch to slope intercept form FIRST!!!!
• THEN GRAPH
You Try!!!
Extra Resources
• http://www.phschool.com/atschool/academy123
/english/academy123_content/wl-bookdemo/ph-214s.html
• http://www.phschool.com/atschool/academy123
/english/academy123_content/wl-bookdemo/ph-213s.html
• http://teachers.henrico.k12.va.us/math/hcpsalge
bra1/Documents/examviewweb/ev6-2.htm
• http://www.phschool.com/webcodes10/index.cf
m?fuseaction=home.gotoWebCode&wcprefix=at
a&wcsuffix=0605
More Resources
•
•
•
•
•
http://www.quia.com/rr/500256.html
http://www.quia.com/quiz/320446.html
http://www.quia.com/cb/79602.html
http://www.quia.com/rr/51535.html
http://www.quia.com/cb/366616.html