1. **Stating the problem:** Write the expressions \(7 \times d\) and \(d \times d\) in correct algebraic notation. 2. **Algebraic notation rules:** - Multiplication between a number and a variable is written by placing them side by side without the multiplication sign. - Multiplication between variables is written by placing the variables side by side. 3. **Expression a:** \[7 \times d = 7d\] This means 7 multiplied by the variable \(d\). 4. **Expression b:** \[d \times d = d^2\] Multiplying a variable by itself is written as the variable raised to the power 2. **Final answers:** - a) \(7d\) - b) \(d^2\)