Can someone help me? :(

How many different ways can you make change for $.50 using only nickels, dimes, and quarters?

The following division is being performed using multiplication by the reciprocal find the missing numbers is 5/12 divided by x/3 equals 5/12 times x/10 equals 1/x

Which of the following quartic functions has x = –1 and x = –2 as its only two real zeroes?