Answer:
7x4+2x3-4x2-5
Step-by-step explanation:
We will start solving this question by opening the bracket first
So let's solve
(7x4+2x3-3)-(4x2-9x+2)
7x4+2x3-3-4x2+9x-2
Collect like terms
7x4+2x3-4x2-3-2
7x4+2x3-4x2-5
So the final answer is 7x4+2x3-4x2-5
