Question #c2eb1

1 Answer
Mar 14, 2017

It doesn't simplify nicely.

Explanation:

You could call #-sqrt(42)-sqrt(42)#
#-2sqrt(42)# if you wanted, the same as calling #-x-x#
negative #-2x#.
Then, if you think of #2# as #sqrt(4)#, then you could call it #-sqrt(4)sqrt(42)#
Using the rule #sqrt(a)sqrt(b)=sqrt(a*b)#, you end up with #-sqrt(168)#. However, that doesn't simplify nicely, so that's about as far as you can go without getting a nasty decimal number (-12.9614814).
In fact, you probably would want to leave it as #-2sqrt(42)#, since that is the simplest radical possible.