1. Let's solve the first algebraic expression: $x + 142 = 16x + 7$. 2. The goal is to isolate $x$ on one side. Start by moving all $x$ terms to one side and constants to the other: $$x - 16x = 7 - 142$$ 3. Simplify both sides: $$-15x = -135$$ 4. To solve for $x$, divide both sides by $-15$: $$x = \frac{-135}{-15}$$ 5. Show the cancellation of negatives: $$x = \frac{\cancel{-135}}{\cancel{-15}} = 9$$ 6. Therefore, the solution is $x = 9$. This means when $x$ is 9, both sides of the original equation are equal.