Solve the equation x + 10x + x + x = 104.

Step-by-step solution

1. 1

   Make the invisible coefficients explicit. A bare $x$ means $1x$, so the left side is $1x + 10x + 1x + 1x$. Treating those bare terms as if they contributed nothing is the standard mistake and would give $10x = 104$.

2. 2

   Add the coefficients.

   $1 + 10 + 1 + 1 = 13 \quad\Longrightarrow\quad 13x = 104$

3. 3

   Divide by the combined coefficient.

   $x = \frac{104}{13} = 8$

   The division is exact because $13 \times 8 = 104$.

4. 4

   Check by substitution. $8 + 10(8) + 8 + 8 = 8 + 80 + 8 + 8 = 104$. Correct.

5. 5

   Note the shape of the problem. This is the algebraic form of a sharing question — four quantities in the ratio $1 : 10 : 1 : 1$ totalling $104$ — so the parts are $8,\ 80,\ 8,\ 8$.