3/4-1/2 can u explain how to do this

With these: 18/36 = 1/? missing number change 1 5/8 to improper fraction. change 19/5 to a mixed number.

He letter p on the number line below represents the number . (use the hyphen for negative numbers and write answer as a decimal, such as –7.2) number line from negative 7 to positive 7 in increments of 0.5 is shown. only the whole numbers are labeled. a point labeled p is placed at the eleventh tick mark to the left of 0.

Whats is the value of the variables ?