What must be subtracted from `4x^4-2x^3-6x^2+x-5` so that the result is exactly divisible by `2x^2+x-1`

Explanation

To solve the problem of what must be subtracted from the polynomial \(4x^4 - 2x^3 - 6x^2 + x - 5\) so that the result is exactly divisible by \(2x^2 + x - 1\), we will perform polynomial long division.

### Step-by-Step Solution:

1. **Set Up the Long Division**:
We will divide \(4x^4 - 2x^3 - 6x^2 + x - 5\) by \(2x^2 + x - 1\).

2. **First Division**:
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