The question does not seem complete, but I'll represent the statement mathematically and look for their ages each. This is because the worst they can ask for is their ages.
Let C stand for Courtney's age, A for Andrei's age, N for Natalie's age and S for Shari's age. From the question we can deduce the following:
C = 2A
C = N + 3
C = S/2
S - N = C + A
S = 2C, N = C - 3 and A = C/2, therefore we have
2C - (C - 3) = C + C/2
C + 3 = C + C/2
C/2 = 3 and C = 6
A = C/2
A= 6/2
A = 3
N = C - 3
N = 6 - 3
N = 3
S = 2C
S = 2 x 6
S = 12.
C = 6, A = 3, N = 3 and S = 12
Answer:
number, variable, or a product of a number and one or more variables
Since the problem is not telling us the height of Silvio, we are going to assume it is not relevant for our calculations.
Let
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the altitude of the incoming plane. We know for our problem that the distance between Silvio and the tower is 3 miles, Also we know that the angle of elevation to the plane is 40°. With this information we can create a triangle as shown in the figure. We need a function that relates the angle of elevation with its opposite and adjacent sides, that function is tangent.
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
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We can conclude that we should use the trig function tangent to model this situation; also, we can conclude that the equation that describes this situation is
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.