Question

6. A diver descends at a rate of 8 m/min. Which expression CANNOT be used to find her depth after 5 minutes?(1 point) Responses −8(5) negative 8 times 5 −8−8−8−8−8 negative 8 minus 8 minus 8 minus 8 minus 8 −8+(−8)+(−8)+(−8)+(−8) negative 8 plus negative 8 plus negative 8 plus negative 8 plus negative 8 −85

Answer 1

To determine which expression cannot be used to find the diver's depth after 5 minutes, we first calculate how deep the diver goes in that time.

The diver descends at a rate of 8 m/min for 5 minutes, so the depth can be calculated as:

\[
\text{Depth} = \text{rate} \times \text{time} = -8 \, \text{m/min} \times 5 \, \text{min} = -40 \, \text{m}
\]

Now let's evaluate the expressions provided:

1. **−8(5)**: This represents the calculation \(-8 \times 5\), which gives \(-40\). This expression can be used.

2. **−8−8−8−8−8**: This expression represents adding up \(-8\) five times, which also equals \(-40\). This expression can be used.

3. **−8+(−8)+(−8)+(−8)+(−8)**: This represents adding \(-8\) five times, equivalent to \(-40\). This expression can be used.

4. **−85**: This evaluates to \(-85\) which does not relate to the diver's depth after 5 minutes, so this expression cannot be used.

Thus, the expression that **CANNOT** be used to find her depth after 5 minutes is:

**−85**.