Vocabulary
What are the three words for slope?
per, every, each
In the calculator, which letter represents the rate of change? What about the y-intercept?
a = rate of change
b = y-intercept
Describe how to find the x-intercept or the y-intercept on a graph.
x-intercept: where the line crosses the x-axis.
y-intercept: where the line crosses the y-axis.
Solve for x:
2(x - 4) =16
x = 12
Lisa is draining the pool in her backyard. Which operation does the word "draining" represent?
subtraction
What is another word for the y-intercept?
initial value, constant, starting amount, one-time fee
What is the slope of these two points?
(-7.5, 12) & (2, -16.5)
-3
You need two "good" points to find slope of a graph.
How do you identify a "good" point?
A "good" point is on the line and whose coordinates are integers (not decimals).
Evaluate y = 4x - 12 when x = -5
y = -32
Tony babysits for $25 an hour. He has already made $100 so far this week. Write an equation that represents y, Tony's total earnings, after babysitting x, hours.
y = 25x + 100
How are the slope of parallel lines and perpendicular lines different?
Parallel lines have the same slopes.
Perpendicular lines have opposite reciprocal slopes.
For slope of a line, you should always begin with the _______ point and you should always move _____ after you either go up or down.
left, right
Describe a graph that has a zero slope.
OR
Describe a graph that has an undefined slope.
zero slope is where the line is horizontal (only crosses the y-axis). EX: y = 3
undefined slope is where the line is vertical (only crosses the x-axis). EX: x = 3
Write the equation in point slope form with a slope of 3 and going through the point (-1, 2).
y - 2 = 3(x + 1)
Dominik is going on a date with a curly-haired cutie. He orders popcorn for $5.50 and each movie ticket costs $12.50.
Write an equation that best represents y, Dominik's total cost, and x, the number of tickets purchased.
y = 12.50x + 5.50
You are asked to substitute x= - 4 into 2(5 - x) + 10.
What does that expression look like after you substitute?
2(5 - - 4) + 10
If the slope is -3/4, then how should you move?
Up? Down? Left? Right?
Down 3, Right 4
What is the slope of x = 3?
undefined slope
Solve for x:
3(x - 2) - 4 = 5
x = 5
Sarah is getting ready for her sister's birthday. She orders cupcakes for $2.75 each. She has already spent $25 on plates and cups.
What is the rate of change in this situation?
$2.75 for each cupcake
How do you know when you should distribute in an equation?
When there are parentheses.
How do you find the slope of a graph?
find two good points, start on the left point, go up or down, and then go right.
What type of slope does a line have if it has an x-intercept of 3 and a y-intercept of 10?
negative slope
Solve for x:
4(3x - 2) = 4x + 8
x = 2
Sarah is getting ready for her sister's birthday. She orders cupcakes for $2.75 each. She has already spent $25 on plates and cups.
If Sarah's budget is $60, then how many cupcakes can she order without going over her spending limit?
12 cupcakes