Systems of Equations

Corissa M. wants to join 1 of 2 gyms near her home. Each gym charges an enrollment fee for joining the gym and a monthly membership fee.

LA Fitness: Enrollment Fee: $55
Monthly Fee: $30


YMCA: Enrollment Fee: $95
Monthly Fee: $25

a. Calculate the cost of a 1-year membership at each gym. Explain all your work.

b. Write an equation for each gym's membership plan that describes the relationship between the number of months of membership (x) and the total cost (y).

c. Determine the number of months at which the total cost of membership at each gym will be the same amount of money. Explain why you did each each step.

Parallel and Perpendicular

David says that the equation y = 0.6x + 4 represents a line that is parallel to the graph of 5y - 3x = 10.

a. Is David correct? Explain how you know.

b. Carlos says that a line perpendicular to y = -6x + 3 would be the line represented by 6y = x + 30. Is Carlos correct? Explain how you know.

**If you need extra help putting the equation into slope intercept form "y=mx + b" check out this website.

http://www.howe-two.com/mathematicat/standardslope.html

Hope this helps!

Inequality

Graph the inequality y > -2x + 3 on the coordinate plane. Explain how you would graph the inequality without a calculator.

Cost of a Call

Here is your first open-ended item. Make sure you "explain how you know" how to solve the problem. Remember, to explain means to to give the meaning of something: give facts and details that make the idea easy to understand.

Question.
The cost of a long distance phone call to Africa is given by the function below where t is time in minutes. C(t) = 1.84 + 0.58t

a. How much will a phone call that last 15 minutes 30 seconds cost? Explain how you know.

b. If the cost of phone call is $5.32, what is the length of the phone call in minutes? Explain how you know.

Rubric

Scoring Rubric for Your Blog Entry

Score (%) In response to this item, the student---


90-100% demonstrates a thorough understanding of how to write and solve a problem from a given situation by correctly solving problems and clearly explaining procedure.


80-89% demonstrates a general understanding of how to write and solve the problem from a given situation by correctly solving problems and clearly explaining procedure with only minor errors or omissions.


65-79% demonstrates a partial understanding of how to write and solve the problem from a given situation by correctly performing a significant portion of the required task.



50-64% demonstrates minimal understanding of how to write and solve the problem from a given situation.


0% The response has given no correct answer and insufficient evidence to demonstrate any understanding of the mathematical concepts and procedures as required by the task. Response may show only information copied from the question or another student.




* Taken from the Pennsylvania Department of Education Bureau of Assessment and Accountability 2009-2010