Explain the standard process for adding and subtracting two fractions?

What is the least common multiple of 6 and 17?

Find the balance at the end of 4 years if 1000 is deposited at the rate of

The area of a rectangle is 15+5y square feet. which of the following expressions could be the length of the sides of the rectangle, in feet a. 5 and 3y b. 5 and 3+y c. 5 and 5+y d. 3 and 5+3y