Please help explanation if possible

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

If myesha works overtime, she gets paid "time and a half" for every hour she works. in other words, for every hour over 40 hours myesha works each week, she gets her hourly pay plus half her hourly pay. what is myesha's pay per hour when she works overtime?

7. if the value of x varies directly with the value of y, and x = 3 when y = 21. what is the valu y, and x = 3 when y = 21. what is the value of x when y = 105?