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 determine 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 can follow these steps:

### Step 1: Define the Polynomials
Let:
- \(p(x) = 4x^4 - 2x^3 - 6x^2 + x - 5\)
- \(q(x) = 2x^2 + x - 1\)

We need to find a polynomial \(r(x)\) such that when subtracted from \(p(x)\), the result \(f(x) = p(x) - r(x)\) is divisible by \(q(x)\).
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