Question

A submarine descends to a depth of 600 feet below the surface in 10 minutes. At this rate, what integer represents the change, in feet, of the submarine's position after one minute?
I really need help.​

Answer 1

A submarine descends to a depth of 600 feet below the surface in 10 minutes. At this rate, what integer represents the change, in feet, of the submarine's position after one minute?

First you need to list what you're given.

A submarine descends to a depth of 600 ft below the surface in 10 minutes. The question is asking for the change of the submarine's position after one minute. This can be represented as fractions in terms of $\frac{distance}{time}$.

$\frac{600}{10} = \frac{x}{1}$

You're looking for the value of x. First you need to cross-multiply.

$600 \times 1 = 10 \times x\\600=10x$

Since you're looking for x alone, you need to divide both sides by 10. This will eliminate the 10 since x is being multiplied by 10, and 10 divided by 10 is 1, making it 1x or x.

$\frac{600}{10} = \frac{10x}{10}$

$60=x$

That means the submarine is descending at a rate of 60 feet per minute, which can be represented as -60.

If you're looking for the submarine's position after one minute, all you have to do is subtract 60.

600 feet below surface is represented as -600.

$-600-60=-660$

The submarine's position after one minute is 660 feet below surface(-660).