Originally Posted by

**702 from 512** I know there are a thousand ways that people try to explain this. In Calculus for dummies it says (This * that + That * this). But this particular software package that I have called Mathtutor which is outstanding does it a bit differently.

I understand everything up until the last part.

Example: Y= ( -2t^2+1) * (3t^2-5)

**Now heres the second to last step to solving the problem:**

Y'= (-12 t^3+ 6t) + (-12 t^3+ 20t)

Ok folks. I understand that you have to add -12 t^3+ -12 t^3 to get 24 t^3.** But what I don't understand is how you do the second part of the equation.**

The answer is Y'= -24 t^3 + 26t

Sometimes from what my software is explaing the problems to me it adds up the last equation sometimes and other times it will do something like

**Y'= -24 t^3 + 20 t - 6t.** **What I need to know is what do you descern to properly do the last part of the equation?**