Question

without actual division,show that 13 is a factor of each of the following numbers a)1313​

Answer 1

Step-by-step explanation:

using divisiblity rule of 13 subtract 13-13×4 and it is divisible by 13 as 13 is common factor and so whole number divisible by 13.

Proof:- for rule of divisiblity let number be of form 10^nx+10^(n-1)y+... and if we subtract last two digit four times or 40ß+4æ and we will have a common factor of 13 it is divisible by 13 as whole digit and rule and related together let's take 1000x+100y+10z+a and so 1000x+100y-30z-3a and also 100xy-3(10z-a) has common factor of 13 and divisible by 13