1. The problem states: "three times a number plus eleven." We want to express this as an algebraic expression. 2. Let the number be represented by the variable $x$. 3. "Three times a number" means multiplying the number by 3, which is $3x$. 4. "Plus eleven" means adding 11 to the product, so the expression becomes $3x + 11$. 5. Therefore, the algebraic expression for "three times a number plus eleven" is: $$3x + 11$$ This expression can be used in equations or further calculations depending on the problem context.