### Instruction: Find $h(x)$, with terms in order of decreasing degree, if  \[3x^4+2x-1+h(x)=5x^2-6x-1.\].### Response: I want to find a function $h(x)$ that makes the equation true for any value of $x$.
To do that, I can try to isolate $h(x)$ on one side of the equation, and then simplify the other side as much as possible.
I can start by subtracting $3x^4+2x-1$ from both sides of the equation, which gives me \[h(x)=-3x^4+5x^2-8x.\]
This is already in order of decreasing degree, so I don't need to do anything else to find $h(x)$.