Answer:
Step-by-step explanation:
The aim of this question is to prove that the product of two rationals is rational.
<u>To proof:</u>
If are arbitrary rational numbers.
Thus, going by the definition of rational, there exist integers
a, b, ≠ 0, c, and d ≠ 0 ;
Hence,
Since a and c are integers, then e = ac appears to be an integer as well.
Also, provided that b and d are non-zero integers;
f =bd appears to be a non-zero integer.
Therefore, , and going by the definition of rational, xy is rational.
Hence, from the complete question:
The order of the statement is:
7,6,3,5,2,4
The statements that should not be used in the proof are:
1 N
8 N
9 N
10 N
11 N