Square roots of negative numbers

This refers back to statements in "Brick Wall" thread. You cannot take the square root of a negative number. Following is a puzzle I've had for days and finally just laid aside as beyond my.



I have a little book called Math in Minutes by Paul Glendinning. It isn't doing exactly what I thought it would do but that's beside the point. It says "200 Key Concepts Explained in an Instant". My problem with it is that it puts all the equations in letters instead of any numerical examples. The result is what happened on the page titled "Squares, square roots, and powers".



Quote: More generally, multiplying a number x by itself n times give x to the power of n, written x (raised n). (P. Glendinning)



I cannot make a raised 'n'; so, shall say "times" instead. The book gives a line of examples, all understandable until I get to the last one:



x times -1 = 1/x. In English, that is an x times -1 equals 1 over (divided by) x.



I hope someone has the skill to put that with raised letters so it looks better. What I do not understand - well, none of it. I had originally intended to ask if someone would use numbers instead of letters and show it working. Now, I think I have to say in complex numbers. Right?



Can anyone write that equation in numbers so that I can see it working? Also, if you cannot take the square root of a negative number surely you also cannot get the square of a negative number?



Please?