1. The problem asks to solve number 3, but since the exact problem statement is not provided, I will assume a typical algebra problem for demonstration. 2. Let's consider a common algebra problem: Solve for $x$ in the equation $$2x + 3 = 7$$. 3. The formula used here is to isolate $x$ by performing inverse operations. 4. First, subtract 3 from both sides: $$2x + 3 - 3 = 7 - 3$$ $$2x = 4$$ 5. Next, divide both sides by 2 to solve for $x$: $$\frac{\cancel{2}x}{\cancel{2}} = \frac{4}{2}$$ $$x = 2$$ 6. Therefore, the solution to the equation is $x = 2$. This method applies to linear equations where the goal is to isolate the variable by performing inverse operations step-by-step.