Use the formula for the area or circumference of a circle to solve the problem. Where applicable, express answers in terms of ?.
Give the exact circumference.
A. 19.5? units
B. 78? units
C. 39? units
D. 1521? units
Answer: C
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Simplify the expression. Assume that all variables are positive when they appear.4
- 3
A. 24
B. 0
C. 12
- 3
D. cannot simplify
Attending concerts is a favorite form of entertainment for many people. The graph shows concert attendance gradually increased from 1994 to 2004 for concerts at a small town's outdoor concert venue. In 1994, the average attendance was 935, as represented by the point src="https://sciemce.com/media/4/ppg__tttt0623191144__f1q89g3.jpg" alt="" style="vertical-align: 0.0px;" height="213" width="361" />Write the system of equations formed from the given points, P and Q, and then solve the system using the elimination method.
A. {(92.0, 34,590)}
B. {(145.7, -239,394)}
C. {(141.5, -281,216)}
D. {(103.5, -204,239)}
In 2004, the average attendance was 2350, as represented by the point 
We can find an equation of the line segment PQ using a system of equations, and then we can use the equation to approximate the attendance in any of the years between 1994 and 2004.
Solve the problem.An object is propelled vertically upward from the top of a 112-foot building. The quadratic function 
models the ball's height above the ground, 
in feet, t seconds after it was thrown. How many seconds does it take until the object finally hits the ground? Round to the nearest tenth of a second if necessary.
A. 2 seconds B. 0.6 seconds C. 5.5 seconds D. 11.6 seconds
Solve the problem.Jim lowers his hot-air balloon by gradually releasing air from the balloon. Let y represent the height of Jim's balloon (in feet) x minutes after he began releasing air from the balloon. Match the correct scenario with the following graph. 
A. Jim released air form the balloon for some time, then stopped to enjoy the countryside, and finally decided to land. B. Jim kept releasing air from the balloon and landed. C. Jim enjoyed the countryside without lowering the balloon. He decided then to lower the balloon, and stayed at this height for a while. Then he decided to land. D. Jim spent hours enjoying the countryside without lowering the balloon, before deciding to land.