1. The problem is to solve a math question suitable for 4eme (8th grade) level in informatique (computer science), but since no specific problem is given, let's consider a common algebra problem: solving a linear equation. 2. The general formula for solving a linear equation $ax + b = 0$ is to isolate $x$ by subtracting $b$ from both sides and then dividing by $a$. 3. For example, solve $3x + 6 = 0$. 4. Subtract 6 from both sides: $$3x + 6 - 6 = 0 - 6$$ $$3x = -6$$ 5. Divide both sides by 3: $$\frac{\cancel{3}x}{\cancel{3}} = \frac{-6}{3}$$ $$x = -2$$ 6. So the solution is $x = -2$. This method applies to any linear equation of the form $ax + b = 0$ where $a \neq 0$.