What is the common denominator of 1/a + 1/b in the complex fraction 1/a - 1/b / 1/a + 1/b

Carlos spent 1 1/4 hours doing his math homework he spent 1/4 of his time practicing his multiplication facts how many hours to carlos been practicing his multiplication facts

What is 1.5% of 120 or what number is 1.5% of 120

If you measured the width of a window in inches and then in feet with measurement would you have the greater number of units