Ashley is on her way home in her car. she has driven 21 miles so far, which is one-third of the way home. what is the total length of her drive?

So if 21 miles is 1/3 of the way you want to multiply 21 by 3 to get 3/3 or the whole way.

21*3=63

The total length of her trip was 63 miles.

If 21 miles is 1/3 the distance home, she must drive 3x the distance to get home. 

21x3=63 miles

The total length of her drive is 63 miles.

Another method is to write an equation, with d being the total distance:
21=1/3d
(3)21=1/3d(3)
63 miles=d

Look, when you want to do something like put it like x^2. x2 could mean x² or x₂. so to clear confusion, know the notation. to find the product multiply the x's and you get -8x and the y's and you get 6y. since it's all being multiplied it is just -8x6y, or answer a. although the better answer is -48xy(combining -8 and 6) because you should multiply constants whenever you can.