Robert earns $512.75 less than Noel. John earns 3 times Robert's salary. If the total salary earned by them is $47,645.25, how much salary does Robert earn?

Robert earned $9426.5

Step-by-step explanation:

Let x represent the amount earned by Robert.

Let y represent the amount earned by Noel.

Let z represent the amount earned by John.

Robert earns $512.75 less than Noel. This is expressed as

y = x + 512.75

John earns 3 times Robert's salary. This is expressed as

z = 3x

If the total salary earned by them is $47,645.25, it means that

x + y + z = 47645.25 - - - - - - - - - - -1

Substituting z =3x and y = x + 512.75 into equation 1, it becomes

x + x + 512.75 + 3x = 47645.25

x + x + 3x = 47645.25 - 512.75

5x = 47132.5

x = 47132.5/5

x = 9426.5

y = x + 512.75 = 9426.5 + 512.75

y = 9939.25

z = 3x = 3 × 9426.5

z = 28279.8

h = 417.81 meters

The altitude of the plane is 417.81 meters

Step-by-step explanation:

given;

The initial height of the girl h0 = 400 m

Horizontal distance from the airport d = 40 m

Angle of elevation of the plane ∅= 24°

The altitude of the plane when the picture was taken is equal to initial height of the girl plus the elevation height.

h = he + h0

And he (elevation height) can be derived as;

he = dtan∅

he = 40tan24°

Substituting into the equation;

h = 40tan24° + 400

h = 417.81 meters

The altitude of the plane is 417.81 meters