Cross multiply the fractions.

Simplify the left side.

Divide by eight on both sides.

Simplify the right side.

The answer is:  

Solve by cross multiplying both fractions.

Instead of multiplying the terms, divide both sides by seven.

Simplify both sides.

Divide by 16 on both sides.

Reduce and simplify both sides.

The answer is:  

Convert the two liters of soda into ounces.

Subtract the four eight-ounce glasses of soda that were poured.

Convert the remaining ounces back into liters.

Alternatively, you could set it up as one equation and solve for , as shown below.

To replace hours with seconds, you must divide by 3600 (seconds in an hour), and to replace miles with feet you must multiply by 5280 (number of feet in a mile).

This problem relies on the formula , or .

Solving for  in the case of both Edward's original trip and the trip Edward will take this time will give us the time each trip would take. The difference between these times is the answer.

The distance Edward travels is  miles. The rate at which he drives on the first trip is  miles per hour. Remember that in writing out equations we can treat the word "per" as a division sign, so we express  as . Solve for  with these numbers in .

To convert the remainder fraction of an hour into minutes, multiply it by .

So the total time for the original trip is  hours and  minutes.

Now use the same  equation, but replace the  miles per hour with  miles per hour for the second trip.

We now know the trip at  miles per hour would be  hours long. Subtracting this from the length of the original  miles per hour trip gives us the amount of time by which this trip would be shorter than the original.

To compare these three different measurements, we need to convert them so they have the same units. Let's convert all three values into meters per second.

Multiplying 70 km/h by 1000 m/km gives us 70,000 meters per hour, and dividing that value by 3600 (since there are 3600 seconds in an hour) gives us 19.4. So, Albert is traveling at 19.4 meters per second.

We convert Katrina's speed in a similar way, multiplying 1.9 km/minute by 1000 m/km and then dividing by 60 (since there are 60 seconds in a minute). These calculations give us 31.67 m/s.

Since both of these values are slower than Joseph's speed of 35 m/s, Joseph is traveling the fastest.

1 meter is equal to 100 centimeters, so 1 cubic meter is equal to cubic centimeters.

1,000,000 cubic centimeters has mass:

1,000 grams are in a kilogram, so convert to kilograms by dividing this number by 1,000:

Let   be the number of map centimeters that represent  kilometers.

Set up a proportion statement which equates two ratios, each of which compares map centimeters to actual kilometers represented. Then solve for 

Let   be the number of map centimeters that represent  kilometers.

Set up a proportion statement which equates two ratios, each of which compares map centimeters to actual kilometers represented. Then solve for 

Let   be the number of actual kilometers represented by  map centimeters.

Set up a proportion statement which equates two ratios, each of which compares actual kilometers represented to map centimeters. Then solve for .