Rotate the coordinate axes through an acute angle ? such that the new equation in x' and y' has no x'y'-term.7x2 + 6
xy + 13y2 = 59
A. y' = 
B. 
+ 
= 1
C. 
+ 
= 1
D. 
+ 
= 1
Answer: D
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The value V, in dollars, of a certain investment after t years is given in the table below. Use exponential regression to determine the percentage decrease in the value of the investment over any 5-year period. Round your answer to two decimal places. t 1 4 7 10 13 V 1,923.61 1,267.27 835.09 550.22 362.38?
A. 65.60% B. 65.00% C. 50.16% D. 51.12%
The data in the figure below represents the number of stars earned by 140 performers in a talent competition.
How many performers earned more than the median number of stars?
A. 91 B. 30 C. 42 D. 49 E. none of these
Solve the problem.In 2008 an outdoor mall was open throughout the year. The number of shoppers averaged 5000 on sunny days, 4000 on cloudy days, 1200 on rainy days, and 3000 on snowy days. The percentage of days of each type in 2008 is given in the following table. Find the average number of average shoppers per day at the mall for 2008. 
A. 3943 B. 3826 C. 3300 D. 2100 E. 1240
Solve the problem.
The Montgomerys borrowed $86,000 at 7.50% for 30 years to purchase a house. Find the total interest the Montomerys will pay if they pay the loan on schedule.
A. $142,794.40 B. $135,673.60 C. $130,410.40 D. $119,884.00