1. **State the problem:**
We want to express the rational function $$\frac{10 - 17x + 14x^2}{(2 + x)(1 - 2x)^2}$$ in partial fractions of the form $$\frac{A}{2 + x} + \frac{B}{1 - 2x} + \frac{C}{(1 - 2x)^2}$$.
2. **Set up the equation:**
$$\frac{10 - 17x + 14x^2}{(2 + x)(1 - 2x)^2} = \frac{A}{2 + x} + \frac{B}{1 - 2x} + \frac{C}{(1 - 2x)^2}$$
Multiply both sides by the denominator $(2 + x)(1 - 2x)^2$ to clear fractions:
$$10 - 17x + 14x^2 = A(1 - 2x)^2 + B(2 + x)(1 - 2x) + C(2 + x)$$
3. **Expand terms:**
- Expand $(1 - 2x)^2 = 1 - 4x + 4x^2$
- Expand $B(2 + x)(1 - 2x)$:
$$ (2 + x)(1 - 2x) = 2 - 4x + x - 2x^2 = 2 - 3x - 2x^2 $$
So,
$$10 - 17x + 14x^2 = A(1 - 4x + 4x^2) + B(2 - 3x - 2x^2) + C(2 + x)$$
4. **Distribute constants:**
$$10 - 17x + 14x^2 = A - 4Ax + 4Ax^2 + 2B - 3Bx - 2Bx^2 + 2C + Cx$$
5. **Group like terms:**
Constant terms:
$$A + 2B + 2C$$
$x$ terms:
$$-4A x - 3B x + C x = (-4A - 3B + C) x$$
$x^2$ terms:
$$4A x^2 - 2B x^2 = (4A - 2B) x^2$$
6. **Equate coefficients:**
From the original polynomial:
- Constant: 10
- Coefficient of $x$: -17
- Coefficient of $x^2$: 14
Set up system:
$$\begin{cases} A + 2B + 2C = 10 \\ -4A - 3B + C = -17 \\ 4A - 2B = 14 \end{cases}$$
7. **Solve the system:**
From the third equation:
$$4A - 2B = 14 \implies 2A - B = 7 \implies B = 2A - 7$$
Substitute $B$ into first and second equations:
- First:
$$A + 2(2A - 7) + 2C = 10 \implies A + 4A - 14 + 2C = 10 \implies 5A + 2C = 24$$
- Second:
$$-4A - 3(2A - 7) + C = -17 \implies -4A - 6A + 21 + C = -17 \implies -10A + C = -38$$
From second:
$$C = -38 + 10A$$
Substitute $C$ into first:
$$5A + 2(-38 + 10A) = 24 \implies 5A - 76 + 20A = 24 \implies 25A = 100 \implies A = 4$$
Then,
$$B = 2(4) - 7 = 8 - 7 = 1$$
$$C = -38 + 10(4) = -38 + 40 = 2$$
8. **Final answer:**
$$\frac{10 - 17x + 14x^2}{(2 + x)(1 - 2x)^2} = \frac{4}{2 + x} + \frac{1}{1 - 2x} + \frac{2}{(1 - 2x)^2}$$
Partial Fractions 4Ebbda
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