1. The problem is to simplify the expression or solve the equation in one calculation line. 2. To do this, we use algebraic rules such as combining like terms, applying distributive property, or simplifying fractions directly. 3. For example, if the problem is to simplify $\frac{2x + 4}{2}$, we can write: $$\frac{2x + 4}{2} = \frac{\cancel{2}(x + 2)}{\cancel{2}} = x + 2$$ 4. This shows the cancellation of common factors in numerator and denominator in one step. 5. Always look for common factors or terms to simplify expressions in one line. 6. If you provide the exact expression, I can show the one-line calculation for it.