1. Problem: Solve the equation $$4x - 12 = 20$$. 2. Formula and rules: To solve linear equations, isolate the variable by performing inverse operations. 3. Step 1: Add 12 to both sides to cancel the -12. $$4x - \cancel{12} + 12 = 20 + 12$$ $$4x = 32$$ 4. Step 2: Divide both sides by 4 to solve for $$x$$. $$\frac{4x}{\cancel{4}} = \frac{32}{\cancel{4}}$$ $$x = 8$$ 5. Explanation: We first removed the constant term on the left by adding 12 to both sides. Then, we divided both sides by the coefficient of $$x$$, which is 4, to isolate $$x$$. The solution is $$x = 8$$. Final answer: $$x = 8$$