1. Let's understand the problem: You are asking what happens when we take common elements like h1, h2, etc., presumably in the context of HTML or CSS selectors. 2. In CSS, selectors like h1, h2, h3 represent different heading levels. Taking them common means grouping selectors to apply the same style rules. 3. The formula or rule used is grouping selectors by separating them with commas, for example: h1, h2, h3 { color: red; } 4. This means the style inside the braces applies to all these selectors simultaneously. 5. Important rule: Grouping selectors reduces repetition and makes CSS more efficient and easier to maintain. 6. Intermediate work: Instead of writing separate rules for h1, h2, h3, you combine them as shown above. 7. Explanation: By taking common selectors, you apply the same styles to multiple elements, saving time and ensuring consistency. Final answer: Taking common selectors like h1, h2, etc., allows you to apply the same CSS styles to all those elements at once by grouping them with commas.