Solve the problem.The intensity of light from a light source varies inversely as the square of the distance from the source. Suppose the the intensity is 40 foot-candles at a distance of 10 feet. What will the intensity be at a distance of 22 feet? Round your answer to the tenths place.

A. 8.5 foot-candles
B. 7.7 foot-candles
C. 8.3 foot-candles
D. 8.0 foot-candles


Answer: C

Mathematics

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Evaluate the function at the given values of the variable.f(x) = x2 + 5a. f(-4)b. f(-6)

A. 80, 180 B. -40, -60 C. -3, -7 D. 21, 41

Mathematics

Solve the problem.Andy decides to fence off a rectangular piece of his land to use as a vegetable garden. He has 80 feet of fencing, so the perimeter of the fenced-in area cannot exceed 80 feet. The length of the garden is to be at least 4 feet longer than the width. Write a system of inequalities that describe this situation and solve the system by graphing. 

A.

B.

C.

D.

Mathematics

Find the equation of the parabola corresponding to the given information.The parabola has focus ( 0 , 3 ) and directrix y = -3.

A. y = x2
B. x = y2
C. y = - x2
D. y = x2

Mathematics

Add. + 927 + 9011

A. 9967
B.
C. 9909
D.

Mathematics