Writing Equations
Slope = -4
y-intercept = 5
y= -4x + 5
What makes a graph proportional? There are two criteria.
Must go through the origin (0,0) and must be a straight line
What are the school colors?
Purple and yellow/gold
What is the equation for slope intercept form?
y = mx + b
Which point is a y-intercept?
(0, 4) or (4, 0)
(0, 4)
Which slope is steeper?
4 or 1/4
4
Slope = 1
and the line passes through the origin
y = x
Is y = 3x proportional?
Yes :-)
What is our school mascot?
Thundercat
What is the slope?
y = 3x - 5
m = 3
The measure of the steepness of a line
What is slope?
Which slope is steeper?
3/4 or 1/2
3/4
Slope = -3
Y-intercept = -5
y= -3x - 5
m = -2
b = 4
proportional?
No, the y-intercept is 4, not 0.
What is our principal's name? (Spelling does not matter)
Dr. Kargbo
What is the y intercept?
y = -3x - 7
b = -7
What is the y-intercept?
Where the line crosses the y-axis
What is the slope of a horizontal line?
Zero!
I have $45 in my account and I add $10 each week to the account.
y= 10x + 45
y = 2x + 14
proportional?
No
How many lunches do we have?
3
Write an equation that has:
Slope: 1/2
Y-intercept: -3
y = 1/2x - 3
How do you find slope on a graph?
Pick two points and calculate the rise/run.
Which slope is steeper:
5/5 or -3/2
-3/2
I have $90 in my account but I spend $20 each week.
y = -20x + 90
Johnny adds 5 dollars to his savings each week. He starts with 10 dollars in his account. Is this a proportional relationship?
No, he had an initial/starting value of 10.
What year did the school open?
2018
Given: y = -1/3x
Find:
m=
b=
m = -1/3
b = 0
What is the slope formula?
(y2-y1 ) / ( x2-x2) or rise/run
Which slope is flatter (less steep)?
-6 or -1/6
-1/6