One way to write the number 7.5 as a fraction is 75/10. This answer is easy to obtain because it only involves moving the decimal one place to the right. Since 7.5 is equal to 7.5 over one, then moving the decimal place to the right gives 75 over 10.
The answer 75/10 can be simplified further to give 15/2. This is done by dividing both the top and the bottom by five. Dividing 75 by five gives 15, and dividing 10 by five gives two. The number five in this example is called the greatest common factor because it is the largest number that divides evenly into both numbers.
A good way to check the answer is to make sure the reverse is true. In this example 15 divided by 2 equals 7.5.