Simplify the Expression: Finding (y×3)² Step by Step

To solve this problem, we will apply the power of a product rule to the given expression $\left(y \times 3\right)^2$.

Let's go through the solution step-by-step:

• Step 1: Understand the expression
  The expression $\left(y \times 3\right)^2$ indicates that the product of $y$ and $3$ is squared. This means we need to apply the square to both terms inside the parentheses.

• Step 2: Apply the power of a product rule
  According to the power of a product rule: $(a \times b)^n = a^n \times b^n$. In our case, $a$ is $y$, $b$ is $3$, and $n$ is $2$. Thus, we have: $(y \times 3)^2 = y^2 \times 3^2$.

Therefore, the correct answer to this problem is $y^2 \times 3^2$, which matches choice 4.