Transcript Using your calculator solve the following

Activity 1 - 10
Leasing a Copier
5-Minute Check on Activity 1-9
1. Using your calculator solve the following:
y = 300
y = 3x2
x = 10, y = 300
Using algebra solve the following:
2. 3x – 7 = 2x + 2
3. 4x – 10 + 2x + 15 = 65
4. 5x = (4x – 15) + 45
5. 45 = (7x + 5) – (2x – 10)
Click the mouse button or press the Space Bar to display the answers.
x=9
x = 10
x=6
x=6
Objectives
• Develop a mathematical model in the form of an
equation
• Solve an equation using an algebraic approach
Vocabulary
• Inverse Operations – doing the opposite of what the
arithmetic operation does (add, then subtract;
multiply, then divide; subtract, then add; divide, then
multiply)
Activity
You are interning at a local law office, Dewey,
Cheetham and Howe. You are asked by the office
manager to gather some information about leasing a
copy machine for the office. The sales representative
at Clorox Copiers recommends a 50-copy per minute
copier to satisfy the office’s copying needs. The copier
leases for $455 per month, plus 1.5 cents a copy.
Maintenance fees are covered in the monthly charges.
The law firm would own the copier after 39 months.
Activity - 1
The copier leases for $455 per month, plus 1.5 cents a
copy. Maintenance fees are covered in the monthly
charges. The law firm would own the copier after 39
months.
a) Identify the independent and dependent variables
Independent: number of copies dependent: cost
b) Write a statement determining the monthly cost
455 rental fee plus 1.5 cents per copy made
c) Complete the table
# of copies
5000
10,000
Monthly cost ($)
530
605
15,000
20,000
680
755
d) Write an equation of the statement in part b
cost = $455 + 0.015copy
Activity - 2
The copier leases for $455 per month, plus 1.5 cents a
copy. Maintenance fees are covered in the monthly
charges. The law firm would own the copier after 39
months.
a) What is the monthly cost of 12,000 copies?
y = f(12000) = 455 + 0.015(12000) = 635
b) 12,000 fits in for the independent or dependent
variable?
independent
c) If the budget only allows $800 for copier expenses,
what is the copy limit?
y = f(x) = 455 + 0.015(x) = 800
345 = 0.015x
23000 = x
Problems
For each of the following, substitute the given value of
y and use an algebraic approach to solve for x
a) y = 3x – 5 where y = 10
10 = 3x – 5
15 = 3x
5=x
b) y = 30 – 2x where y = 24
24 = 30 – 2x
-6 = -2x
3=x
c) y = (3/4)x – 21 where y = -9
-9 = (3/4)x – 21
12 = (3/4)x
16 = x
d) y = 15 – 2x where y = -3
-3 = 15 – 2x
-18 = -2x
9=x
Summary and Homework
• Summary
– The goal of solving an equation, ax + b = c, is to
isolate the variable x on one side of the equation
x = ….
– Use inverse operations to isolate the variable
• Undo the addition by subtracting b from both
sides of the equation
• Undo the multiplication by dividing both sides
of the equation by a
• Homework
– pg 89-93; 6-10