When doing this kind of problem, we're going to look at just the numerator portion by itself to start. So our thought ought to be, is the denominator a monomial? And Z + d is 2 terms, so it's not a single term. There's nothing we can factor out of it other than we could pull out A1 as a placeholder. We might not need to do that, but it might help to see that now it is a monomial. The second term currently is a monomial also because it is a single term in the denominator. So now when I look for the common denominator between the two, they have to be exactly the same. Z + d is not exactly the same as Z so I actually need the common denominator to be Z * Z + d And if I look at this first one right here, I need to multiply that by AZ on top and bottom to get this new common denominator. So if I multiply by AZ on top and AZ on bottom, that would give me the new common denominator. So I'd get one time Z or plain old Z on top. Then we have minus and we have this new common denominator of Z * Z + d and the second term had A1 over Z. Well, right, there's the Z. But I need AZ plus D in the denominator also. So I'm going to have to multiply by Z + d in the top and Z + d in the denominator in order to get the common denominator. 1 * Z + d is going to be Z + d So if we keep going with this, we're now going to have AZ minus the quantity Z + d in the numerators all over Z * Z + d If we distribute out the negative, we get Z -, Z -, d / Z * Z + d or negative d / Z * Z + d Now that's just the numerator. So that's this top part. Now we need to divide that by D so I have negative d / Z * Z + d / d So if I think about dividing by, that's really the same thing as multiplying by one over its reciprocal. So if we have this and we multiply by 1 / d, now everything's still a monomial because everything is just either in parentheses or straight multiplication or division. So this D in the numerator and this D in the denominator are actually going to cancel because we know anything over itself reduces to 1. So once those two cancel, we get a final answer of -1 / Z * Z + d.