1. Let's state a similar problem: Solve for $x$ in the equation $$2x + 5 = 15$$. 2. The formula used here is to isolate $x$ by performing inverse operations. Important rules: addition and subtraction undo each other, multiplication and division undo each other. 3. Subtract 5 from both sides: $$2x + 5 - 5 = 15 - 5$$ which simplifies to $$2x = 10$$. 4. Divide both sides by 2 to solve for $x$: $$\frac{2x}{2} = \frac{10}{2}$$ which simplifies to $$x = 5$$. 5. So, the solution to the equation is $x = 5$. This example shows how to solve a simple linear equation by isolating the variable step-by-step.