Question 471803
Any number that is to 1 in the same ratio as two natural numbers, is called a rational number.  A rational number, then, is any number that we could write as a fraction.


We have seen that EVERY FRACTION   {{{a/b}}}  has the same ratio to {{{1}}} as the numerator has to the denominator: {{{(a/b) : 1  =  a : b}}}.

{{{(3/4)(5/7)=3*5/4*7=15/28}}}

proof:
{{{(15/28):1=15:28}}}

{{{(15/28)/(1/1)=15/28}}}

{{{(15*1/28*1)=15/28}}}

{{{15/28=15/28}}}........rational

use same way to prove the following problems

{{{-5+3/5=-25/5+3/5=-22/5}}}


{{{2/3-3/5=2*5/3*5-3*3/5*3=10/15-9/15=1/15}}}


{{{(2/5)/5=(2/5)/(5/1)=2*5/5*1=2/1}}}

so, all are rational numbers