إذا كان |س + س| = 10، فإن قيمة س تساوي:

$$س + س = 2س$$

The equation becomes:

$$|2س| = 10$$

The absolute value of $2س$ being 10 means that $2س$ can be either 10 or $-10$.
Case 1:

$$2س = 10$$

Case 2:

$$2س = -10$$

Case 1:

$$س = \frac{10}{2}$$ $$س = 5$$

Case 2:

$$س = \frac{-10}{2}$$ $$س = -5$$

The possible values for $س$ are 5 and $-5$.
The given options are:
1: ٢ (2)
2: ٣ (3)
3: ٤ (4)
4: ٥ (5)

The value $س = 5$ matches option 4.