NAME:
REGULAR QUIZ #4
MATH 084.09
11 / 20 / 2012
(The number of points for each problem is noted in parentheses.)
(2) 1. (a) Graphically solve the system of equations:
9x − y = 7
2x + y = 4
(b) Solve the same system of equations by substitution or elimination.
(1) 2. How many solutions are there for the following systems of equations:
(a) −8x + 2y = 15
(b) y = ── x − ──
y = 4x + 3
−2x + 4y = −3
(1) 3. Rewrite as a fraction in lowest terms the following repeating decimal: 0.18
(1) 4. Solve the following system of equations:
── x = − ── y − 1
5x − 2y = 65
(1) 5. Brass is an alloy of copper and zinc. Brass A is 65% copper. Brass B is 80% copper.
Brass C is 68% copper. Write a system of equations that would make it possible to find the
amount of Brass A and Brass B needed to make 500 kilograms of Brass C. Clearly state the
meaning of the unknowns.
(1) 6. Solve the following system of equations by elimination: 5x + 2y = 3
6x − 7y = 13
(1) 7. The perimeter of a rectangle is 44 cm. The width is 6 cm shorter than the length.
Find the length and width of the rectangle.
(1) 8. A credit card user is shifting her balances. Her total debt is $1950. She wants four
times as much debt on her VISA card than on her MasterCard. How much debt should be
on each card?
(1) 9. Three pounds of lemon drops and five pounds of chocolates cost $14. Seven pounds
of lemon drops and nine pounds of chocolates cost $26. Write a system of equations that
would allow you to find the cost of a pound of lemon drops and the cost of a pound of
chocolates. Clearly state the meaning of the unknowns.
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