Question

name christian
homework due: wednesday, january 21, 2026: rational number arithmetic:

1. when a construction worker is on a platform 10 feet above the ground, we can

describe her elevation as +10 feet.

a. a construction worker digs down to 30 feet below the surface of the ground.
what is her elevation?

b. the construction worker returns to the surface of the ground. what is her
elevation?

Explanation:

Part a

Step1: Define elevation sign

Above ground is positive, so below ground is negative.

Step2: Determine elevation

She is 30 feet below ground, so elevation is $-30$ feet.

Step1: Understand ground level

The surface of the ground is the reference point (0 elevation for above/below).

Step2: Determine elevation

When on the ground surface, elevation is 0 feet.

Answer:

-30 feet

Part b