1. Today:
 Warm-Up/Final Exam Review
 Formula Review
 Point-Slope Formula
 Examples & Practice
 Class Work 2.11
15TH

2. Our 1st Coordinate Plane Test :
Wednesday, Jan. 21; The Test will include the following:
 Functions, Domain, Range
 Ordered Pairs
 Standard & Slope Intercept Forms of a Line
Khan Academy:
As you’ve probably realized,
there is no KA this week.
However, there will be one for next week,
and will be posted shortly.
At the V6math site.....

3. The Ultimate Guide to the coordinate plane.
75 slides, start to finish step-by-step review of the entire unit.
Includes practice problems with solutions. Yours to download.

4. Warm Up
1. What is 250% of 18?
3. 24 is reduced by 25%; what number could you
multiply 24 by to get the answer?
2. 7|x−10|−9 = 54
4. A simplified number is .45 more than 50% of 3/5.
Qual è il numero?
5. The sum of 3 numbers is 112. The second number is
25% larger than the first, while the third number is 75%
larger than the first. What are the numbers?
x + 1.25x + 1.75x = 112 ; x = 28; x1 = 35; x2 = 49
For #1; Mentis Arithmetica
Formula & Vocabulary Section of your Notebook

5. The Point-Slope Form of a Line:
The last pieces of the coordinate puzzle are the point-
slope formula and the slope of a line formula.
4) Point-Slope form of a line
Soon, you’ll be able to take any linear equation and
create the graph of that equation.
You will also be able to take any line or any points on a
graph, and be able to determine the equation for that line.
You will have to memorize the following four formulas:
1) Standard Form of a line equation
2) Slope - Intercept Form Equation
3) Slope of a line formula

6. Coordinate Plane Formulas:
Standard Form of a linear equation: Ax + By = C
A, B, & C are all constants and..
a.) A and B are not both zero.
b.) The largest exponent is not greater than 1
The slope is the change in y divided by the change in x as we
move along the line from (x1, y1) to (x2, y2).
change in y
change in x
Rise
Run
=Slope of a line:
The slope is m and the y-intercept is (0, b).
Slope-Intercept Form:
y = mx + b

7. A linear equation written in the form y – y1 = m(x – x1) is in
point-slope form. (y is the letter, y1 is the coordinate)
The Point-Slope Form of a Line:
When you do not have the complete graph or the equation:
Example: Write the equation and graph the line that has a
slope of 2 and passes the point (-2,4)
y – 4 = 2(x – -2)
y – 4 = 2x + 𝟒 y = 2x + 8
All you have is one of the points passing through (x1, y1), and
the slope (m) of the line.
In this situation, you begin to construct the equation by using
the point-slope form of a line.
y – y1 = m(x – x1)

8. (4, 3)
m = -
1
3
x
y
4
4
8
8
What is the y-intercept?
4
𝟏
𝟑
Now, determine where the
line crosses the x-axis?
slope of -
𝟏
𝟑
and passes the point (4,3)
y =
Put the equation in
standard form first.
Divide each term by
𝟏
𝟑
(y is zero)
x + 0 =
𝟐𝟒
𝟑
= 8
Use the point-slope formula to draw the line that has a....
y – y1 = m(x – x1)
y- 3 = -
𝟏
𝟑
(x – 4)
-
𝟏
𝟑
x + 4
𝟏
𝟑
Find the x-intercept

9. The Point-Slope Form of a Line:
Example 1: Write the equation of the line passing
through the point (-2, 5) with a slope of 3.
Use the point-slope form, y – y1 = m(x – x1), with
m = 3 and (x1, y1) = (-2, 5).
y – y1 = m(x – x1) Point-slope form
y – y1 = 3(x – x1) Let m = 3.
y – 5 = 3(x – (-2)) Let (x1, y1) = (-2, 5).
y – 5 = 3(x + 2) y = 3x + 11
You begin by using the Point-Slope form of a line
and finish with what form of a line??

10. Other Examples:

11. Be Careful Here
y =
𝟐
𝟓
x + 2
y = -
𝟐
𝟑
x - 2
Other Examples:
Write the equation of each line in both standard and
slope-intercept forms. The equations should have
integers only (no fractions)
5y = 𝟐x + 10 2x - 5y = −10
standard form is...

12. Graphing Stories

13. Follow Closely:
Graphing Stories

14. Graphing Stories

15. Class Work 2.11;
Show All Work