1. The problem is not clearly stated, but since you mentioned "for senior 4," I assume you want a general algebra problem suitable for senior 4 level. 2. Let's solve a common algebra problem: Solve for $x$ in the equation $$2x + 3 = 11$$. 3. The formula used here is to isolate $x$ by performing inverse operations. 4. Step 1: Subtract 3 from both sides: $$2x + 3 - 3 = 11 - 3$$ which simplifies to $$2x = 8$$. 5. Step 2: Divide both sides by 2: $$\frac{2x}{2} = \frac{8}{2}$$ which simplifies to $$x = 4$$. 6. Therefore, the solution is $x = 4$. This method applies the principle of maintaining equality by performing the same operation on both sides of the equation to isolate the variable.