So the derivative of this first expression, 3 times 4 is 12. 12x squared, we just decrement the 3 by 1, times the second expression, times x to the fourth plus 27 to the minus 1. And then to that we want to add just the first expression, not its derivative, so just 4x to the third, times the derivative of the second expression. So the second expression, we could take the derivative of the inside, which is just 4x to the third, this derivative of 27 is just 0. So times 4x to the third, times the derivative of this whole thing with respect to the inside. So times, so you take this exponent, put it out front. So times minus 1, times this whole thing, x to the fourth plus 27, to the, we decrement this by 1 more, so minus 2.