Solve for Y

1
Solve for Y
Algebra Notes - Slope of a Line
Cant add or sub these Why? They are not Like
Terms

• We want y by itself
• Move the x term (do the opposite or -)
• Move the term in front of y (do the opposite x or
  )
• Slope _____
• Y-intercept ___
• write it as

2
C
________ Slopes
________ Slopes
D
B
E
A
Read line from left to right Going
up______ Going down--________
3
Types of lines
Angles up Angles down Horizontal
Vertical
Slope is ______ Slope is ________
Slope is ______ Slope is _____
4
Find slope from a graph

• Slope is a fraction
• How far did you go up/down?
• Over
• How far did you left/right?
• Slope

Going up is Positive
right is Positive
left is Negative
Write this on notes
Going down is Negative
5
B
Read line from left to right Going up
Going down--
A
6
Find slope from a graph

• Pick two points on the grid
• Starting from left pt, count up or down on grid
• Write down that number in the numerator
• Count left or right to next point
• Write down this number in denominator
• This fraction is your slope

Going up is Positive
right is Positive
left is Negative
Going down is Negative
7
C
D
8
E
Read line from left to right Going up
Going down--
F
9
Steps to find slope from 2 pts

• (x1, y1) (x2, y2)
• (2, 7) (8, 3)
• Formula
• (it will be given to you)

• Label your points

10
Example 1

• (x1, y1) (x2, y2)
• (0, 4) (1, 2)

• Label your points

11
Example 2

• (7, -4) (9, -1)

• Label your points
• (x1, y1) (x2, y2)
• Plug points into formula
• Simplify top and bottom, then divide the two
  numbers
• Calculator (y2 - y1) divide (x2- x2) enter

12
Example 3-4

• (x1, y1) (x2, y2)
• (10, 5) (3, 5)

(x1, y1) (x2, y2) (-4, 2) (-4, 0)
3)
4)