Question

a two digit number is 4 times the sum of its digits if we interchange the digits the number obtained is 9 less than the orignal number. find the number

Answer 1

Here is ur answer...

Answer 2

Answer:

12

Step-by-step explanation:

A two digit number is 4 times the sum of its digits if we interchange the digits the number obtained is 9 more than the original number. find the number.

Let the two digit number is xy

we know that we can write it as= 10x+y

Sum of digits= x+y

According to the question:

$10x + y = 4(x + y) \\ \\ 10x + y = 4x + 4y \\ \\ 6x - 3y = 0 \\ \\ 2x - y = 0 \: \: \: ...eq1$

On interchanging the digits number can be written as 10y+x

if we interchange the digits the number obtained is 9 more than the orignal number

So

$10y + x = 10x + y+9 \\ \\ - 9x + 9y = 9 \\ \\ x - y = -1 \: \: \: \: ..eq2$

Solve eq1 and eq2

$2x - y = 0 \\ x - y = -1 \\ ( - ) \: ( + ) \: ( +) \\ - - - - - - \\ x = 1 \\ y = 2$

Thus the two digit number is 12.

Hope it helps you.

Note*: question must reframe.