Finding the missing term, in matrix arrangement

Question

Find the missing term $x$. I am not able to guess the pattern $$\begin{pmatrix}811 & 236 & 57 \\ 23 & 87 & 119\\ 314 & 70 & x\end{pmatrix}$$

Answer 1

Transposition of digits of one operand allows to build the chain of summations: \begin{align} &\mathbf{118}+\mathbf{118} = 236,\quad 236+\mathbf{78} = 314,\quad 57+87 = \mathbf{134}, \quad\mathbf{32}+87=119\dots \end{align} Term $\underline{x=94}$ allows to close the chain: $$94+87 = \mathbf{181},\quad \mathbf{49} + 70 = 119,\quad 87+\mathbf{7}= 94.$$

Answer 2

I found the same question here where it was multiple choice. The choices were $87,12,57,61$. Two people chose $87$. The only one who presented a reason said to add the digits of each number until you are down to a single digit. Equivalently, reduce each number $\bmod 9$. Then the third column is the sum of the first two. Without the choices this is not enough to pick $87$, you just know you want something equivalent to $6 \bmod 9$. The only choice that fits is $87$. The setter claims the answer is $61$ but does not provide the reason. That is the most credible source I can find.

Answer 3

The term "pattern" is not a mathematical, precisely-defined, rigorous term.

Therefore, the question has no sense.

If you want to answer it correctly, you can answer : "I found the missing term $x$, it is at the bottom right of the matrix. Have you any maths questions ? Thanks !".