Simplify Rational
1. Problem 30: Simplify the expression $$\frac{2}{x+1} + \frac{1}{x-2} - \frac{1}{x^2 - 1}$$.
2. First, factor the denominator of the third term: $$x^2 - 1 = (x-1)(x+1)$$.
3. Find a common denominator for all terms: it is $$(x-2)(x-1)(x+1)$$.
4. Rewrite each fraction with the common denominator:
$$\frac{2}{x+1} = \frac{2(x-2)(x-1)}{(x+1)(x-2)(x-1)}$$
$$\frac{1}{x-2} = \frac{1(x-1)(x+1)}{(x-2)(x-1)(x+1)}$$
$$-\frac{1}{(x-1)(x+1)} = -\frac{(x-2)}{(x-2)(x-1)(x+1)}$$
5. Combine the numerators:
$$2(x-2)(x-1) + (x-1)(x+1) - (x-2)$$.
6. Expand each term:
$$2(x^2 - 3x + 2) + (x^2 - 1) - (x - 2) = 2x^2 - 6x + 4 + x^2 - 1 - x + 2$$
7. Simplify the numerator:
$$3x^2 - 7x + 5$$
8. So the simplified expression is:
$$\frac{3x^2 - 7x + 5}{(x-2)(x-1)(x+1)}$$, which matches option (c).
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9. Problem 31: Simplify $$\frac{1}{x-3} + \frac{1}{x+3}$$.
10. Find common denominator: $$(x-3)(x+3) = x^2 - 9$$.
11. Rewrite:
$$\frac{1(x+3)}{x^2-9} + \frac{1(x-3)}{x^2-9} = \frac{x+3 + x - 3}{x^2 - 9} = \frac{2x}{x^2 - 9}$$.
12. This is option (b).
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13. Problem 32: Simplify $$-\frac{2}{x} + \frac{1}{x-1} + \frac{1}{x+1}$$.
14. Common denominator is $$x(x-1)(x+1) = x(x^2 -1)$$.
15. Rewrite each:
$$-\frac{2(x-1)(x+1)}{x(x^2-1)} + \frac{1 \cdot x (x+1)}{x(x^2-1)} + \frac{1 \cdot x(x-1)}{x(x^2-1)}$$
16. Expand numerators:
$$-2(x^2 -1) + x(x+1) + x(x-1) = -2x^2 + 2 + x^2 + x + x^2 - x$$
17. Simplify numerator:
$$(-2x^2 + x^2 + x^2) + (x - x) + 2 = 0 + 0 + 2 = 2$$
18. So the expression is:
$$\frac{2}{x(x^2 -1)}$$, matching option (c).
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19. Problem 33: Simplify $$\frac{x^2 - 3x + 2}{x^2 + 5x + 4} \times \frac{x+1}{x-1}$$.
20. Factor all polynomials:
$$x^2 -3x + 2 = (x-1)(x-2)$$
$$x^2 + 5x +4 = (x+4)(x+1)$$
21. Substitute:
$$\frac{(x-1)(x-2)}{(x+4)(x+1)} \times \frac{x+1}{x-1}$$
22. Cancel common factors $$(x+1)$$ and $$(x-1)$$:
$$\frac{(x-2)}{(x+4)}$$
23. Matches option (c).
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24. Problem 34: Simplify $$\frac{4x^2 -4}{x^2 + 2x + 1} \cdot \frac{x+1}{x-1}$$.
25. Factor:
$$4x^2 -4 = 4(x^2 -1) = 4(x-1)(x+1)$$
$$x^2 + 2x + 1 = (x+1)^2$$
26. Substitute:
$$\frac{4(x-1)(x+1)}{(x+1)^2} \cdot \frac{x+1}{x-1}$$
27. Cancel $$(x+1)$$ and $$(x-1)$$ terms:
$$\frac{4}{x+1} \cdot 1 = \frac{4}{x+1}$$
28. Matches option (b).
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29. Problem 35: Simplify $$\frac{x^2-9}{x^2 + 6x +9} \cdot \frac{x+3}{x-9}$$.
30. Factor:
$$x^2 - 9 = (x-3)(x+3)$$
$$x^2 + 6x +9 = (x+3)^2$$
31. Substitute:
$$\frac{(x-3)(x+3)}{(x+3)^2} \cdot \frac{x+3}{x-9} = \frac{x-3}{x+3} \cdot \frac{x+3}{x-9}$$
32. Cancel $$(x+3)$$:
$$\frac{x-3}{x-9}$$
33. Matches option (a).
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34. Problem 36: Simplify $$\frac{3x^2 -12}{x+2} \cdot \frac{x}{x-2}$$.
35. Factor numerator:
$$3x^2 - 12 = 3(x^2 -4) = 3(x-2)(x+2)$$
36. Substitute:
$$\frac{3(x-2)(x+2)}{x+2} \cdot \frac{x}{x-2}$$
37. Cancel $$(x+2)$$ and $$(x-2)$$:
$$3 \cdot x = 3x$$
38. Matches option (a).
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39. Problem 37: Simplify $$\frac{2 - 3x - 2x^2}{x^2 + 3x} \div \frac{x^2 + 3x + 2}{x+3}$$.
40. Factor denominators:
$$x^2 + 3x = x(x+3)$$
$$x^2 + 3x + 2 = (x+1)(x+2)$$
41. Rewrite division as multiplication by reciprocal:
$$\frac{2 - 3x - 2x^2}{x(x+3)} \times \frac{x+3}{(x+1)(x+2)}$$
42. Cancel $$(x+3)$$:
$$\frac{2 - 3x - 2x^2}{x} \times \frac{1}{(x+1)(x+2)}$$
43. Factor numerator $2 - 3x - 2x^2$:
Rewrite as:
$$-2x^2 - 3x + 2$$
Try to factor:
$$(2x+1)(-x+2) = -2x^2 + 3x + 2$$ which is close but sign differs.
Try:
$$(1 - 2x)(x + 1) = x + 1 - 2x^2 - 2x = -2x^2 - x + 1$$ no.
Try grouping:
No simple factorization; keep as is.
44. So expression is:
$$\frac{2 - 3x - 2x^2}{x(x+1)(x+2)}$$
Rewrite numerator as $$1 - 2x - x^2$$ by rearrangement? No perfect match.
Try rewriting numerator as $$1 - 2x - x^2$$: Actually original numerator is $$2 - 3x - 2x^2$$.
Try factor by trial:
Factorizing: roots from quadratic equation
$$-2x^2 - 3x + 2 = 0$$
Multiply both sides by -1:
$$2x^2 + 3x - 2 = 0$$
Roots:
$$x = \frac{-3 \pm \sqrt{9 + 16}}{4} = \frac{-3 \pm 5}{4}$$
Roots:
$$x = \frac{2}{4} = \frac{1}{2}$$ or $$x = \frac{-8}{4} = -2$$
So factor:
$$2x^2 + 3x - 2 = (2x -1)(x + 2)$$
Therefore original numerator:
$$-(2x^2 + 3x - 2) = -(2x -1)(x + 2) = (1 - 2x)(x + 2)$$
45. Substitute numerator:
$$\frac{(1 - 2x)(x+2)}{x(x+1)(x+2)} = \frac{1 - 2x}{x(x+1)}$$
46. Matches option (c).
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47. Problem 38: Simplify $$\frac{x + 2}{1 + \frac{2}{x}}$$.
48. Rewrite denominator:
$$1 + \frac{2}{x} = \frac{x + 2}{x}$$
49. So expression is:
$$\frac{x + 2}{\frac{x + 2}{x}} = (x + 2) \times \frac{x}{x + 2} = x$$
50. Matches option (a).