<PRE><B>Question 1085460</B>
&lt;pre&gt;
Time = (7x-2y) hours
Rate = (49x&lt;sup&gt;2&lt;/sup&gt;+14xy+4y&lt;sup&gt;2&lt;/sup&gt;) kilometers per hour

The formula is

Distance = Rate × Time

Distance = (49x&lt;sup&gt;2&lt;/sup&gt;+14xy+4y&lt;sup&gt;2&lt;/sup&gt;)(7x-2y)

Now simplify this:

If you switch the factors (7x-2y)(49x&lt;sup&gt;2&lt;/sup&gt;+14xy+4y&lt;sup&gt;2&lt;/sup&gt;) 
and recognize this as the factorization of (7x)&lt;sup&gt;3&lt;/sup&gt;-(2y)&lt;sup&gt;3&lt;/sup&gt;,
then you&#39;ll know this is the answer. Otherwise, multiply it
all the way out and everything will cancel except 343x&lt;sup&gt;3&lt;/sup&gt;-8y&lt;sup&gt;3&lt;/sup&gt;, 
which = (7x)&lt;sup&gt;3&lt;/sup&gt;-(2y)&lt;sup&gt;3&lt;/sup&gt;.

Edwin&lt;/pre&gt;</PRE>