The user-friendly version of this content is available here.

The following content is copyright (c) 2009-2013 by Goods of the Mind, LLC.

This problem trains for: SAT-I, SAT-II, AMC-8, AMC-10, Math Kangaroo 5-6, Math Kangaroo 7-8.

If the following is a proportion:

Evaluate the expression:

Given the proportion:

The product of the means (inner terms) is equal to the product of the extremes (outer terms):

We can substitute this value for ab in the expression:

Instead of blindly executing operations, we can apply clever transformations: