you have to multiply the top and bottom number by the same number
Add the letter "n" after the first article. That is, change "a" to "an".
17/8 = 15/8
12
No.
Some numbers are improper fractions and some are not. For example, 1/2 or 0.5 is a number but not an improper fraction. And there is no way in which you can express it as an improper fraction.