Which expression is equivalent to
3(x+2)(x-1)+5x(x-1)

3(x + 2)(x - 1) + 5x(x - 1)

Distribute 3 into the parenthesis:

(3x + 6)(x - 1) + 5x(x - 1)

Distribute 3x + 6 into the parenthesis:

3x^2 - 3x + 6x - 6 + 5x(x - 1)

Combine like terms:

3x^2 + 3x - 6 + 5x(x - 1)

Distribute 5x into the parenthesis:

3x^2 + 3x - 6 + 5x^2 - 5x

Combine like terms:

8x^2 - 2x - 6