1. State the problem: Create two similar algebraic problems without solutions. 2. Problem 1: Solve for $x$ in the equation $$3x + 5 = 20$$. 3. Problem 2: Solve for $x$ in the equation $$4x - 7 = 21$$. These problems are similar because both require isolating $x$ by performing inverse operations on linear equations. No answers are provided as requested.