All natural numbers can be presented in the fraction form with a denominator 1 (5=5/1, 8=8/1, etc.). An inverse number for natural is the fraction with the denominator equal to this number, and the numerator equal to unit.
If you take a common fraction 2/3 and will rearrange numerator and a denominator, then receive 3/2, i.e. fraction, the return this. In other words, to receive the return fraction for a common fraction, it is necessary to trade places numerator and a denominator. Using this rule, you can find the fraction return for any fraction. For example, for fraction 3/4 the return 4/3, for 6/5 – 5/6. Two fractions having property when the numerator of the first is a denominator of the second, and a denominator of the first – numerator of the second, are the mutually return. Pay attention that for fraction 1/5 the return there will be a fraction 5/1 or simply 5. Finding fraction, the return given, you received an integer. And this case not single as for all fractions with the numerator equal to unit, integers will be the return. For example, for fraction 1/6 – the return fraction will be number 6, for 1/8 – 8. As when determining the return fractions is passed to face integers, mathematicians use a concept not the "return fractions", namely "inverse numbers". So, to write down an inverse number for fraction, it is necessary to trade numerator and a denominator places. The same way it is possible to receive an inverse number and for an integer as for any integer it is possible to mean the denominator equal to unit. Means, number 7 will be the return for 1/7 as 7=7/1; for number 11 the return will be 1/11 as 11=11/1. This formulation can be expressed in other words: the number, the return given, is by division of unit into this number. This rule is applicable not only to integers, but also to fractions. For example, if it is necessary to write an inverse number 3/4, then it is possible 1 to divide into 3/4 and to receive 4/3 (1:3/4=1x3/4=3/4). The main property of inverse numbers is that their work is equal to unit. And it is valid, at 3/4x4/3=1, 1/7x7/1=1. Thus, two numbers which work is equal 1 are called the mutually return.