1. The problem is to solve an algebraic expression or equation suitable for grade 9 CBSE level. Since no specific equation is given, let's consider a common example: Solve for $x$ in the equation $2x + 3 = 11$. 2. The formula or rule used here is to isolate the variable $x$ by performing inverse operations. Important rules: - Addition and subtraction are inverse operations. - Multiplication and division are inverse operations. 3. Start by subtracting 3 from both sides to isolate the term with $x$: $$2x + 3 - 3 = 11 - 3$$ which simplifies to $$2x = 8$$ 4. Next, divide both sides by 2 to solve for $x$: $$\frac{2x}{2} = \frac{8}{2}$$ which simplifies to $$x = 4$$ 5. Therefore, the solution to the equation $2x + 3 = 11$ is $x = 4$. This method can be applied to similar linear equations by performing inverse operations step-by-step to isolate the variable.