Question

6.1.2 exam: semester exam
after swimming to a depth of 50 feet below the surface of
the water, a fish swims back up 30 feet. use a number line
to help you create an equation that shows the new location
of the fish in relation to the water’s surface.

number line image

interpret the sum in the context of the problem.

a. the equation is -50 + (-30) = -20. the fish is 20 feet below the
water’s surface.

b. the equation is -50 + 30 = -80. the fish is 80 feet below the
water’s surface.

c. the equation is -50 + (-30) = -80. the fish is 80 feet below the
water’s surface.

d option partially visible

Explanation:

Step1: Define surface as 0, depth as negative

Let water surface = $0$, depth below = negative value.

Step2: Set initial position

Initial position: $-50$ (50 ft below surface)

Step3: Add upward movement

Upward 30 ft = $+30$. Equation: $-50 + 30$

Step4: Calculate final position

$-50 + 30 = -20$

Step5: Interpret result

$-20$ means 20 ft below surface.

Answer:

D. The equation is $-50 + 30 = -20$. The fish is 20 feet below the water's surface.