7.3E: Exercícios
- Page ID
- 183652
A prática leva à perfeição
Adicione e subtraia expressões racionais com um denominador comum
Nos exercícios a seguir, adicione.
1. \(\dfrac{2}{15}+\dfrac{7}{15}\)
- Responda
-
\(\dfrac{3}{5}\)
2. \(\dfrac{7}{24}+\dfrac{11}{24}\)
3. \(\dfrac{3c}{4c−5}+\dfrac{5}{4c−5}\)
- Responda
-
\(\dfrac{3c+5}{4c−5}\)
4. \(\dfrac{7m}{2m+n}+\dfrac{4}{2m+n}\)
5. \(\dfrac{2r^2}{2r−1}+\dfrac{15r−8}{2r−1}\)
- Responda
-
\(r+8\)
6. \(\dfrac{3s^2}{3s−2}+\dfrac{13s−10}{3s−2}\)
7. \(\dfrac{2w^2}{w^2−16}+\dfrac{8w}{w^2−16}\)
- Responda
-
\(\dfrac{2w}{w−4}\)
8. \(\dfrac{7x^2}{x^2−9}+\dfrac{21x}{x^2−9}\)
Nos exercícios a seguir, subtraia.
9. \(\dfrac{9a^2}{3a−7}−\dfrac{49}{3a−7}\)
- Responda
-
\(3a+7\)
10. \(\dfrac{25b^2}{5b−6}−\dfrac{36}{5b−6}\)
11. \(\dfrac{3m^2}{6m−30}−\dfrac{21m−30}{6m−30}\)
- Responda
-
\(\dfrac{m−2}{2}\)
12. \(\dfrac{2n^2}{4n−32}−\dfrac{18n−16}{4n−32}\)
13. \(\dfrac{6p^2+3p+4}{p^2+4p−5}−\dfrac{5p^2+p+7}{p^2+4p−5}\)
- Responda
-
\(\dfrac{p+3}{p+5}\)
14. \(\dfrac{5q^2+3q−9}{q^2+6q+8}−\dfrac{4q^2+9q+7}{q^2+6q+8}\)
15. \(\dfrac{5r^2+7r−33}{r^2−49}−\dfrac{4r^2+5r+30}{r^2−49}\)
- Responda
-
\(\dfrac{r+9}{r+7}\)
16. \(\dfrac{7t^2−t−4}{t^2−25}−\dfrac{6t^2+12t−44}{t^2−25}\)
Adicione e subtraia expressões racionais cujos denominadores são opostos
Nos exercícios a seguir, adicione ou subtraia.
17. \(\dfrac{10v}{2v−1}+\dfrac{2v+4}{1−2v}\)
- Responda
-
\(4\)
18. \(\dfrac{20w}{5w−2}+\dfrac{5w+6}{2−5w}\)
19. \(\dfrac{10x^2+16x−7}{8x−3}+\dfrac{2x^2+3x−1}{3−8x}\)
- Responda
-
\(x+2\)
20. \(\dfrac{6y^2+2y−11}{3y−7}+\dfrac{3y^2−3y+17}{7−3y}\)
21. \(\dfrac{z^2+6z}{z^2−25}−\dfrac{3z+20}{25−z^2}\)
- Responda
-
\(\dfrac{z+4}{z−5}\)
22. \(\dfrac{a^2+3a}{a^2−9}−\dfrac{3a−27}{9−a^2}\)
23. \(\dfrac{2b^2+30b−13}{b^2−49}−\dfrac{2b^2−5b−8}{49−b^2}\)
- Responda
-
\(\dfrac{4b−3}{b−7}\)
24. \(\dfrac{c^2+5c−10}{c^2−16}−\dfrac{c^2−8c−10}{16−c^2}\)
Encontre o denominador menos comum de expressões racionais
Nos exercícios a seguir, a. encontre o LCD para as expressões racionais dadas b. reescreva-as como expressões racionais equivalentes com o menor denominador comum.
25. \(\dfrac{5}{x^2−2x−8},\dfrac{2x}{x^2−x−12}\)
- Responda
-
a.\((x+2)(x−4)(x+3)\)
b.\(\dfrac{5x+15}{(x+2)(x−4)(x+3)}\),
\(\dfrac{2x^2+4x}{(x+2)(x−4)(x+3)}\)
26. \(\dfrac{8}{y^2+12y+35},\dfrac{3y}{y^2+y−42}\)
27. \(\dfrac{9}{z^2+2z−8},\dfrac{4z}{z^2−4}\)
- Responda
-
a.\((z−2)(z+4)(z−4)\)
b.\(\dfrac{9z−36}{(z−2)(z+4)(z−4)}\),
\(\dfrac{4z^2−8z}{(z−2)(z+4)(z−4)}\)
28. \(\dfrac{6}{a^2+14a+45},\dfrac{5a}{a^2−81}\)
29. \(\dfrac{4}{b^2+6b+9},\dfrac{2b}{b^2−2b−15}\)
- Responda
-
a.\((b+3)(b+3)(b−5)\)
b.\(\dfrac{4b−20}{(b+3)(b+3)(b−5)}\),
\(\dfrac{2b^2+6b}{(b+3)(b+3)(b−5)}\)
30. \(\dfrac{5}{c^2−4c+4},\dfrac{3c}{c^2−7c+10}\)
31. \(\dfrac{2}{3d^2+14d−5},\dfrac{5d}{3d^2−19d+6}\)
- Responda
-
a.\((d+5)(3d−1)(d−6)\)
b.\(\dfrac{2d−12}{(d+5)(3d−1)(d−6)}\),
\(\dfrac{5d^2+25d}{(d+5)(3d−1)(d−6)}\)
32. \(\dfrac{3}{5m^2−3m−2},\dfrac{6m}{5m^2+17m+6}\)
Adicione e subtraia expressões racionais com denominadores diferentes
Nos exercícios a seguir, execute as operações indicadas.
33. \(\dfrac{7}{10x^2y}+\dfrac{4}{15xy^2}\)
- Responda
-
\(\dfrac{21y+8x}{30x^2y^2}\)
34. \(\dfrac{1}{12a^3b^2}+\dfrac{5}{9a^2b^3}\)
35. \(\dfrac{3}{r+4}+\dfrac{2}{r−5}\)
- Responda
-
\(\dfrac{5r−7}{(r+4)(r−5)}\)
36. \(\dfrac{4}{s−7}+\dfrac{5}{s+3}\)
37. \(\dfrac{5}{3w−2}+\dfrac{2}{w+1}\)
- Responda
-
\(\dfrac{11w+1}{(3w−2)(w+1)}\)
38. \(\dfrac{4}{2x+5}+\dfrac{2}{x−1}\)
39. \(\dfrac{2y}{y+3}+\dfrac{3}{y−1}\)
- Responda
-
\(\dfrac{2y^2+y+9}{(y+3)(y−1)}\)
40. \(\dfrac{3z}{z−2}+\dfrac{1}{z+5}\)
41. \(\dfrac{5b}{a^2b−2a^2}+\dfrac{2b}{b^2−4}\)
- Responda
-
\(\dfrac{b(5b+10+2a^2)}{a^2(b−2)(b+2)}\)
42. \(\dfrac{4}{cd+3c}+\dfrac{1}{d^2−9}\)
43. \(\dfrac{−3m}{3m−3}+\dfrac{5m}{m^2+3m−4}\)
- Responda
-
\(-\dfrac{m}{m+4}\)
44. \(\dfrac{8}{4n+4}+\dfrac{6}{n^2−n−2}\)
45. \(\dfrac{3r}{r^2+7r+6}+\dfrac{9}{r^2+4r+3}\)
- Responda
-
\(\dfrac{3(r^2+6r+18)}{(r+1)(r+6)(r+3)}\)
46. \(\dfrac{2s}{s^2+2s−8}+\dfrac{4}{s^2+3s−10}\)
47. \(\dfrac{t}{t−6}−\dfrac{t−2}{t+6}\)
- Responda
-
\(\dfrac{2(7t−6)}{(t−6)(t+6)}\)
48. \(\dfrac{x−3}{x+6}−\dfrac{x}{x+3}\)
49. \(\dfrac{5a}{a+3}−\dfrac{a+2}{a+6}\)
- Responda
-
\(\dfrac{4a^2+25a−6}{(a+3)(a+6)}\)
50. \(\dfrac{3b}{b−2}−\dfrac{b−6}{b−8}\)
51. \(\dfrac{6}{m+6}−\dfrac{12m}{m^2−36}\)
- Responda
-
\(\dfrac{−6}{m−6}\)
52. \(\dfrac{4}{n+4}−\dfrac{8n}{n^2−16}\)
53. \(\dfrac{−9p−17}{p^2−4p−21}−\dfrac{p+1}{7−p}\)
- Responda
-
\(\dfrac{p+2}{p+3}\)
54. \(\dfrac{−13q−8}{q^2+2q−24}−\dfrac{q+2}{4−q}\)
55. \(\dfrac{−2r−16}{r^2+6r−16}−\dfrac{5}{2−r}\)
- Responda
-
\(\dfrac{3}{r−2}\)
56. \(\dfrac{2t−30}{t^2+6t−27}−\dfrac{2}{3−t}\)
57. \(\dfrac{2x+7}{10x−1}+3\)
- Responda
-
\(\dfrac{4(8x+1)}{10x−1}\)
58. \(\dfrac{8y−4}{5y+2}−6\)
59. \(\dfrac{3}{x^2−3x−4}−\dfrac{2}{x^2−5x+4}\)
- Responda
-
\(\dfrac{x−5}{(x−4)(x+1)(x−1)}\)
60. \(\dfrac{4}{x^2−6x+5}−\dfrac{3}{x^2−7x+10}\)
61. \(\dfrac{5}{x^2+8x−9}−\dfrac{4}{x^2+10x+9}\)
- Responda
-
\(\dfrac{1}{(x−1)(x+1)}\)
62. \(\dfrac{3}{2x^2+5x+2}−\dfrac{1}{2x^2+3x+1}\)
63. \(\dfrac{5a}{a−2}+\dfrac{9}{a}−\dfrac{2a+18}{a^2−2a}\)
- Responda
-
\(\dfrac{5a^2+7a−36}{a(a−2)}\)
64. \(\dfrac{2b}{b−5}+\dfrac{3}{2b}−\dfrac{2b−15}{2b^2−10b}\)
65. \(\dfrac{c}{c+2}+\dfrac{5}{c−2}−\dfrac{10c}{c^2−4}\)
- Responda
-
\(\dfrac{c−5}{c+2}\)
66. \(\dfrac{6d}{d−5}+\dfrac{1}{d+4}+\dfrac{7d−5}{d^2−d−20}\)
67. \(\dfrac{3d}{d+2}+\dfrac{4}{d}−\dfrac{d+8}{d^2+2d}\)
- Responda
-
\(\dfrac{3(d+1)}{d+2}\)
68. \(\dfrac{2q}{q+5}+\dfrac{3}{q−3}−\dfrac{13q+15}{q^2+2q−15}\)
Adicionar e subtrair funções racionais
Nos exercícios a seguir, encontre a.\(R(x)=f(x)+g(x)\)\(R(x)=f(x)−g(x)\) b.
69. \(f(x)=\dfrac{−5x−5}{x^2+x−6}\)e\( g(x)=\dfrac{x+1}{2−x}\)
- Responda
-
a.\(R(x)=−\dfrac{(x+8)(x+1)}{(x−2)(x+3)}\)
b.\(R(x)=\dfrac{x+1}{x+3}\)
70. \(f(x)=\dfrac{−4x−24}{x^2+x−30}\)e\( g(x)=\dfrac{x+7}{5−x}\)
71. \(f(x)=\dfrac{6x}{x^2−64}\)e\(g(x)=\dfrac{3}{x−8}\)
- Responda
-
a.\(R(x)=\dfrac{3(3x+8)}{(x−8)(x+8)}\)
b.\(R(x)=\dfrac{3}{x+8}\)
72. \(f(x)=\dfrac{5}{x+7}\)e\( g(x)=\dfrac{10x}{x^2−49}\)
exercícios de escrita
73. Donald acha que\(\dfrac{3}{x}+\dfrac{4}{x}\) sim\(\dfrac{7}{2x}\). Donald está correto? Explique.
- Responda
-
As respostas podem variar.
74. Explique como você encontra o denominador menos comum de\(x^2+5x+4\)\(x^2−16\) e.
75. Felipe acha\(\dfrac{1}{x}+\dfrac{1}{y}\) que sim\(\dfrac{2}{x+y}\).
a. Escolha valores numéricos para x e y e avalie\(\dfrac{1}{x}+\dfrac{1}{y}\).
b. Avalie\(\dfrac{2}{x+y}\) os mesmos valores de x e y que você usou na parte a.
c. Explique por que Felipe está errado.
d. Encontre a expressão correta para\(1x+1y\).
- Responda
-
a. As respostas podem variar.
b. As respostas podem variar.
c. As respostas podem variar.
d.\(\dfrac{x+y}{x}\)
76. Simplifique a expressão\(\dfrac{4}{n^2+6n+9}−\dfrac{1}{n^2−9}\) e explique todas as suas etapas.
Verificação automática
a. Depois de concluir os exercícios, use esta lista de verificação para avaliar seu domínio dos objetivos desta seção.
b. Depois de analisar essa lista de verificação, o que você fará para se tornar confiante em todos os objetivos?