Perform the indicated operations and express your answer in the form a + bi. 
A. 9i
B. -9i
C. ±9
D. i
Answer: A
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Find the area of the specified region.Inside the circle r = 
sin ? and outside the cardioid r = 1 + cos ?
A. 
B. 
C. 
D. 
Solve using Cramer's Rule.Linear systems occur in the design of roof trusses for new homes and buildings. The simplest type of roof truss is a triangle. The truss shown in the figure is used to frame roofs of small buildings. If a 109-pound force is applied at the peak of the truss, then the forces or weights W1 and W2 exerted parallel to each rafter of the truss are determined by the following linear system of equations. Solve the system to find W1 and W2. src="https://sciemce.com/media/4/ppg__tttt0508191537__f1q46g3.jpg" style="vertical-align: -4.0px;" />W1 - 
W1 + 
W2 = 218 
W2 = 0
A. W1 = 97.73 lb; W2= 79.79 lb
B. W1 = 39.9 lb; W2= 48.86 lb
C. W1 = 79.79 lb; W2= 97.73 lb
D. W1 = 109 lb; W2= 133.5 lb
Find the perimeter of the figure.
13
A. 26
B. 26
C. 52
D. 52
Solve the problem. Write ratios in lowest terms.A certain lake is 700 feet deep. A nearby lake is 1300 feet deep. Write the ratio of the first lake's depth to the second lake's depth.
A. 
B. 
C. 
D. 