Question

The elevation of city A is 96 feet below sea level; the elevation of city C is 24 feet below sea level. The elevation of city D is 1 over 4 of the elevation of city C.
Part A: Write an expression to represent the elevation, in feet, of city D. (5 points)

Part B: Solve the expression and explain why the answer is negative or positive. (5 points)

Answer 1

Answer:

Given:

Elevation of city A = -96 ft (below sea level)

Elevation of city C = -24 ft (below sea level)

Let x =  elevation of city D.

Part A.

Because the elevation of city D is 1/4 of the elevation of city C, therefore

x = (1/4)*(-24)

Part B.

Because 24/4 = 6, therefore

x  = -6 ft.

Answer:

The elevation of city D is 6 feet below sea level.

The answer is negative because the elevation is below sea level.

Answer 2

We shall use a negative sign for an elevation below sea level, and a positive sign for an elevation above sea level.

Given:
Elevation of city A = -96 ft (below sea level)
Elevation of city C = -24 ft (below sea level)

Let x =  elevation of city D.

Part A.
Because the elevation of city D is 1/4 of the elevation of city C, therefore
x = (1/4)*(-24)

Part B.
Because 24/4 = 6, therefore
x  = -6 ft.

Answer:
The elevation of city D is 6 feet below sea level.
The answer is negative because the elevation is below sea level.