The term 3x^2 has a coefficient of 3, which means that the coefficient of x^2 in the expression 3x^2 - 4x + 15 is 3.

To find the coefficient of x^2 in a quadratic expression of the form ax^2 + bx + c, you simply look at the coefficient a.

In this case, a = 3, so the coefficient of x^2 is 3.

In simply :

Here are the steps to finding the coefficient of x^2 in the expression 3x^2 - 4x + 15:

1. Identify the quadratic term. In this case, the quadratic term is 3x^2.

2. Recall that the coefficient of a term is the number in front of the variable. In the term 3x^2, the coefficient is 3.

3. Therefore, the coefficient of x^2 in the expression 3x^2 - 4x + 15 is 3.

I hope that helps!