How are (3x) ^2 and 3x^2 different?

In (3x) ^2, you are squaring both the 3 and the x:

9x^2

in 3x^2, you are squaring just the x:

3x^2

(3x) ^2=9x^2

(3x^2) = 3x^2

Step-by-step explanation:

The difference between the two is that

(3x) ^2 means the square applied to both the 3 and the x to give 9x^2

But on the other side

(3x^2) means that the square only applies to x without involving 3 which gives 3x^2

So there is difference between them