3x(x-2)-5x(x+3)

To simplify the expression 3x(x-2)-5x(x+3), you need to apply the distributive property and combine like terms.

First, let's expand the expression:

3x(x-2) = 3x * x - 3x * 2 = 3x^2 - 6x

-5x(x+3) = -5x * x - 5x * 3 = -5x^2 - 15x

Now, let's simplify the expression by combining like terms:

3x^2 - 6x - 5x^2 - 15x

Combining like terms, -6x and -15x, we get -21x.

So, the simplified expression is:

-2x^2 - 21x