What is the similarity in- the difference between a two-digit number and the sum of it's digits?

Answer 1

It's always divisible by 9

Answer 2

A two-digit number can be written 10t + u, where t and u are positive integers such that:
1 ≤ t ≤ 9 and 0 ≤ u ≤ 9.

The sum of the digits is t + u.

What's the similarity between t + u and 10t + u?
They'll always differ by 9t. In other words, if you subtract the sum of the digits from the original two-digit number, the difference is always 9 times the original ten's digit, t.

Examples:
23 - 5 = 18 = 9(2).
47 - 11 = 36 = 9(4).
96 - 15 = 81 = 9(9).

Answer 3

The sum of it's digits subtracted from the original number is always an exact multiple of 9.
e.g.
52 => 5+2=7 => 52-7 = 45 = 5*9
86 => 8+6=14 => 86-14=72 = 8*9


Doug

Answer 4

Equation which describes any 2 digit number for x and y less than 10

10x + y

Sum of the digits = x + y

10x + y - (x + y) = 9x

Therefore the relationship is take the 10's digit and multiply by 9 to get the answer.

Answer 5

two digit number is 10*a + b; with a>0 b>=0 natural.

the difference between a two-digit number and the sum of it's digits is : 10a + b -a -b = 9a.
thus the difference is always divisble by 9 and by the second digit a.

Answer 6

A two digit number would have the digits t and o. The value of that number would be 10t+o. The sum of its digits would be t+o. The difference between the two would then be 9t.

Answer 7

The sum of the resulting digits will always be 9.

Answer 8

You will always get a multiple of 9

Answer 9

I'm not really sure what youre asking, but why don't you try it out?

11-2 = 10
12-3=9
etc.

Answer 10

(10x + y) - (x + y)
10x + y - x - y
(10 - 1)x + (1 - 1)y
9x

ANS : 9x