How do you change a mixed number to an improper fraction?

Example: 2 1/2 = 5/2
You change a mixed number into an improper fraction by multiplying the whole number by the denominator and the add that onto the numerator. In the example shown above, you times the whole number (2) by the denominator (2) which equals 4, and then add that onto the numerator (1) which equals 5. So it becomes 5 over two. Hope this helps

20y5 times 2 is 1010 times -2 is -20, plus y