A seal went 15 feet below sea level to catch a fish. A sea lion dove 6 feet less than two times as deep as the seal to catch a larger fish. What expression represents the sea lion’s position in relation to sea level?

2 times 15 minus 6
15 minus 2 times 6
2 times (negative 15) minus 6
2 times (negative 15) minus (negative 6)

1 answer

To find the expression that represents the sea lion's position in relation to sea level, we start with the information given about the seal's position.

The seal is at a depth of 15 feet below sea level, which can be represented as -15 feet.

The sea lion dove 6 feet less than two times the depth of the seal. The expression for this can be constructed as follows:

  1. Two times the depth of the seal is \(2 \times (-15) = -30\).
  2. Six feet less than that is \(-30 - 6\).

Combining the two steps gives us:

\[ -30 - 6 = -36 \]

Thus, the sea lion dove to a depth of 36 feet below sea level.

Now, looking at the provided options:

  1. 2 times 15 minus 6: This would give \(30 - 6 = 24\) (not correct).
  2. 15 minus 2 times 6: This would give \(15 - 12 = 3\) (not correct).
  3. 2 times (negative 15) minus 6: This would give \(-30 - 6 = -36\) (correct).
  4. 2 times (negative 15) minus (negative 6): This would give \(-30 + 6 = -24\) (not correct).

Thus, the correct expression that represents the sea lion’s position in relation to sea level is 2 times (negative 15) minus 6.