The multiplicative inverse of a number is a number such that . Clearly, .
So what must you multiply by -1 in order to achieve a result of 1?
By the way, the multiplicative inverse of a number is also referred to as the reciprocal of a number. The process is fairly straight-forward. Turn the number into a fraction (if it is an integer, make it a fraction with a denominator of 1), and then turn the fraction upside down. If you recall when you learned how to divide fractions ("invert and multiply") you were simply being taught that to divide, you multiply by the reciprocal or multiplicative inverse.
John
My calculator said it, I believe it, that settles it
