Cost Equation
How do you determine the difference between fixed cost and variable cost?
What is the variable cost changes
What is the slope formula
y2-y1/x2-x1
What is the slope- intercept formula
y=mx+b
What is standard form
Ax+By=C
What are the three steps to writing an equation from 2 points
1) Calculate the slope
2) Calculate the b (y-int)
3) Write the equation
To bowl at Rock N Bowl, it costs $2 per game plus $3 for shoe rental. The total cost, y in dollars, depends on x, the number of games played. Write an equation to represent this situation.
y = 2x+3
What is the slope of the equation y=4x+3
m=4
How do you solve an equation written in this form?
Using Inverse Operations
What variable do you solve for to convert from standard form to slope intercept
Y
Which step do you skip to when the slope and y-int are given
Step 3
An editor charges $30 for each hour he works on a book project, plus a flat $25 editing fee. How many hours of work are included in a $190 bill for a project?
5.5 hours
What is the slope of the equation 10x + 5y = 15
m = 2
Write the equation: m = 2 (1,3)
y = 2x + 1
What is 21x + 3y = 15 in slope intercept form
y = -7x + 5
Which 2 steps do you need to complete if finding the equation using a graph
Steps 1 & 3
Fred works at a car wash where he makes $40 per day plus $1.75 per car that he washes. Yesterday, Fred made a total of $75. How many cars did he wash yesterday?
He washed 20 cars
(5, -2) and (5, 8)
m = Undefined
What is the RoC and starting value of the equation; y = -x + 5
m = -1
b = 5
What is the y-intercept of the line determined by the equation 5x - 2y - 9 = 0
-9/2
Write the equation for the line that passes through (-1,0) and (0,-2)
y = -2x - 2
The fixed costs of printing certain text books is $1000 per week. The variable costs are $2.50 per textbook. Which of the following expressions can be used to model the cost of printing, t, textbooks in 1 week.
a)1002.50t
b) 2.50t - 1000
c)1000t + 2.50
d) 1000 + 2.50t
D) 1000 + 2.50t
Diastolic blood pressure tends to increase linearly with age. Suppose that the average diastolic blood pressure of a 20-year old is 120 and the average diastolic blood pressure of a 60-year old is 140. Given this model, what would be the average diastolic blood pressure of a 50-year old?
y = 135
To become an all star library member, there is a monthly charge of $2 after an initial charge. John paid a total of $78 after 19 months. Write an equation that gives the total cost of the membership as a function of the length of the membership in months. Find the total cost of the membership after 2 years. (Must identify all parts)
b = 40
y = 2x + 40
y = 88
In standard form: What is the equation of the line that passes through the points (-4,5) and (-8,-15)?
5x - y = -25
In BMX racing, racers purchase a one-year membership to the track. They also pay an entry fee for each race at that track. One racer paid a total of $125 after 5 races. A second racer paid a total of $170 after 8 races. Write an equation that represents this equation. ( All parts should be identified on your board)
m = 15
b = 50
y = 15x + 50