If ` 98215"x"2` is a number with `"x"` as its tens digit such that it is divisible by 4. Find all possible values of `x` .

Explanation

A number is divisible by `4` only when the number formed by its digits in unit’s and ten’s place is divisible by `4`.
i.e., `x^2` is divisible by `4`
Expanding `x^2`,
`10x+2=` multiple of `4`
Here `x^2` can take values `2,12,22,32,42,52,62,72,82,92`
So values `12,32,52,72` and `92` are divisible by `4`.
Hence, `x` can take values `1,3,5,7` and `9`.