Your expression looks like this: . The mathematical operation indicated by that is multiplication. We will distribute the 3/4 into the 5z by multiplication. If it's easier, think of the problem like this: . When you multiply fractions you don't need a common denominator. You just multiply straight across the top and straight across the bottom. 3 times 5z is 15, and 4 times 1 is 4 so that comes to . And 3 times 16 is 48, and 4 times 1 is 4, and 48/4 is 12. So the final simplified expression is . Your answer is B.