Question

Find the value of x for which the number x806 is divisible by 9. Also, find the number.

Answer 1

For a number to be divisible by 9, the sum of the digits must be divisible by 9.

Sum of the digits in the given number = $x+8+0+6=x+14$

The sum of the digits is divisible by 9, only in the following case:

$$\begin{gathered} x=4 \\ or \\ x+14=18 \end{gathered}$$

Thus, the number x806 is divisible by 9 if $x$ is equal to 4.

The number is 4806.