(1)) Which expression is equivalent to \( 2(5 j+4) \) ?

To simplify the expression \( 2(5j + 4) \), you can distribute the \( 2 \) to both terms inside the parentheses. This means multiplying \( 2 \) by \( 5j \) and \( 2 \) by \( 4 \). So, you get: \[ 2 \times 5j + 2 \times 4 = 10j + 8. \] Therefore, the expression equivalent to \( 2(5j + 4) \) is \( 10j + 8 \). If you want to deepen your understanding, consider that distributing is a fundamental algebraic skill. It's like spreading out ingredients evenly in a recipe, ensuring that everything combines well. Moreover, practicing these types of simplifications can bolster your confidence not just in algebra, but also in math-related fields like physics and engineering, where these principles frequently apply in solving equation systems or modeling real-world phenomena.