Algebra
Equazioni di secondo grado
equazioni monomie
1 𝑥𝑥2 = 0 3𝑥𝑥2 = 0
2 5
7 𝑥𝑥2 = 0 2
3 𝑥𝑥2 = 0
3 4𝑥𝑥2 = 0 10𝑥𝑥2 = 0
equazioni pure
4 𝑥𝑥2− 1 = 0 𝑥𝑥1= −1, 𝑥𝑥2= 1 𝑥𝑥2 − 4 = 0 𝑥𝑥1= −2, 𝑥𝑥2= 2
5 3𝑥𝑥2− 27 = 0 𝑥𝑥1= −3, 𝑥𝑥2= 3 9𝑥𝑥2 − 4 = 0 𝑥𝑥1= −2 3 , 𝑥𝑥2=2
3
6 𝑥𝑥2+ 1 = 0 ∄ 𝑥𝑥 ∈ 𝑅𝑅 𝑥𝑥2 + 9 = 0 ∄ 𝑥𝑥 ∈ 𝑅𝑅
7 3𝑥𝑥2− 1 = 0 𝑥𝑥1= −√3
3 , 𝑥𝑥2=√3
3 5𝑥𝑥2 + 125 = 0 ∄𝑥𝑥 ∈ 𝑅𝑅
8 125𝑥𝑥2− 5 = 0 𝑥𝑥1= −1
5 , 𝑥𝑥2=1
5 4 + 124𝑥𝑥2 = 0 ∄ 𝑥𝑥 ∈ 𝑅𝑅
9 𝑥𝑥2− √2 = 0 𝑥𝑥1= −√24 , 𝑥𝑥2= √24 √3𝑥𝑥2+ 1 = 0 ∄ 𝑥𝑥 ∈ 𝑅𝑅
10 7
8 𝑥𝑥2− 1 = 0 𝑥𝑥1= −2√14
7 , 𝑥𝑥2=2√14 7
4
5 𝑥𝑥2 − 49 = 0 𝑥𝑥1= −7√5
2 , 𝑥𝑥2=7√5 2
11 7 + 49𝑥𝑥2 = 0 ∄ 𝑥𝑥 ∈ 𝑅𝑅 7 − 49𝑥𝑥2 = 0 𝑥𝑥1= −√7
7 , 𝑥𝑥2=√7 7
12 5𝑥𝑥2 = 1 𝑥𝑥1= −√5
5 , 𝑥𝑥2=√5
5 7 = −3𝑥𝑥2 ∄ 𝑥𝑥 ∈ 𝑅𝑅
equazioni spurie
13 𝑥𝑥2− 𝑥𝑥 = 0 𝑥𝑥1= 0, 𝑥𝑥2= 1 3𝑥𝑥2 + 5𝑥𝑥 = 0 𝑥𝑥1= 0, 𝑥𝑥2= −5 3
14 7
9 𝑥𝑥2− 𝑥𝑥 = 0 𝑥𝑥1= 0, 𝑥𝑥2=9
7 𝑥𝑥2 + 4𝑥𝑥 = 0 𝑥𝑥1= 0, x2= −4
15 𝑥𝑥2+2
3 𝑥𝑥 = 0 𝑥𝑥1= 0, 𝑥𝑥2= −
2
3 5𝑥𝑥2 + 10𝑥𝑥 = 0 𝑥𝑥1= 0, 𝑥𝑥2= −2
16 81
4 𝑥𝑥2−9
2 𝑥𝑥 = 0 𝑥𝑥1= 0, 𝑥𝑥2=
2 9
9
4 𝑥𝑥2 −2
3 𝑥𝑥 = 0 𝑥𝑥1= 0, 𝑥𝑥2=
8 27 17 𝑥𝑥 − 2𝑥𝑥2 = 0 𝑥𝑥1= 0, x2=1
2 2𝑥𝑥 + 𝑥𝑥2 = 0 𝑥𝑥1= 0, 𝑥𝑥2= −2
18 3
5 𝑥𝑥2+ 𝑥𝑥 = 0 𝑥𝑥1= 0, 𝑥𝑥2= −5 3
25
49 𝑥𝑥2 + 𝑥𝑥 = 0 𝑥𝑥1= 0, 𝑥𝑥2= −49 25 19 5𝑥𝑥 = 5𝑥𝑥2 𝑥𝑥1= 0, x2= 1 5𝑥𝑥 − 3𝑥𝑥2 = 0 𝑥𝑥1= 0, 𝑥𝑥2=5
3
Algebra
Equazioni di secondo grado
20 𝑥𝑥2 = √5𝑥𝑥 𝑥𝑥1= 0, 𝑥𝑥2= √5 √2𝑥𝑥2 = −2𝑥𝑥 𝑥𝑥1= 0, 𝑥𝑥2= −√2
equazioni complete
21 𝑥𝑥2− 7𝑥𝑥 + 10 = 0 𝑥𝑥1= 2, 𝑥𝑥2= 5
22 𝑥𝑥2+ 5𝑥𝑥 + 6 = 0 𝑥𝑥1= −3, 𝑥𝑥2= −2
23 𝑥𝑥2+ 2𝑥𝑥 − 3 = 0 𝑥𝑥1= −3, 𝑥𝑥2= 1
24 2𝑥𝑥2+ 7𝑥𝑥 + 3 = 0 𝑥𝑥1= −3, 𝑥𝑥2= −1
2
25 𝑥𝑥2+ 𝑥𝑥 + 12 = 0 ∄ 𝑥𝑥 ∈ 𝑅𝑅
26 5𝑥𝑥2− 2x − 16 = 0 𝑥𝑥1= −8
5 , 𝑥𝑥2= 2
27 2𝑥𝑥2+ 5𝑥𝑥 − 12 = 0 𝑥𝑥1= −4, 𝑥𝑥2=3
2
28 25𝑥𝑥2− 20𝑥𝑥 + 4 = 0 𝑥𝑥1= 𝑥𝑥2=2
5
29 𝑥𝑥2− 5𝑥𝑥 + 6 = 0 𝑥𝑥1= 2, 𝑥𝑥2= 3
30 𝑥𝑥2+ 𝑥𝑥 − 12 = 0 𝑥𝑥1= −4, 𝑥𝑥2= 3
31 𝑥𝑥2+ 7𝑥𝑥 − 8 = 0 𝑥𝑥1= −8, 𝑥𝑥2= 1
32 9𝑥𝑥2− 6𝑥𝑥 + 1 = 0 𝑥𝑥1= 𝑥𝑥2=1
3
33 𝑥𝑥2− 𝑥𝑥 = 20 𝑥𝑥1= −4, 𝑥𝑥2= 5
34 3𝑥𝑥2+ 5𝑥𝑥 + 3 = 0 ∄ 𝑥𝑥 ∈ 𝑅𝑅
35 2𝑥𝑥2 = 3𝑥𝑥 + 2 𝑥𝑥1= −1
2 , 𝑥𝑥2= 2
36 𝑥𝑥2 = 𝑥𝑥 + 2 𝑥𝑥1= −1, 𝑥𝑥2= 2
Algebra
Equazioni di secondo grado
37 10 = 3𝑥𝑥2 + 𝑥𝑥 𝑥𝑥1= −2, 𝑥𝑥2=5
3
38 𝑥𝑥2− 3√2𝑥𝑥 + 4 = 0 𝑥𝑥1= √2, 𝑥𝑥2= 2√2
39 3𝑥𝑥2− 𝑥𝑥 + 1 = 0 ∄ 𝑥𝑥 ∈ 𝑅𝑅
40 4𝑥𝑥2− 4𝑥𝑥 − 1 = 0 𝑥𝑥1=1 − √2
2 , 𝑥𝑥2=1 + √2 2
41 𝑥𝑥2+ 4𝑥𝑥 + 1 = 0 𝑥𝑥1= −2 − √3, 𝑥𝑥2= −2 + √3
42 𝑥𝑥2 = −𝑥𝑥 − 2 ∄ 𝑥𝑥 ∈ 𝑅𝑅
43 𝑥𝑥2− �√3 + √2�𝑥𝑥 + √6 = 0 𝑥𝑥1= √2, 𝑥𝑥2= √3
44 (2𝑥𝑥 + 1)2− (𝑥𝑥 − 3)2 = 0 𝑥𝑥1= −4, 𝑥𝑥2=2
3
45 𝑥𝑥 = (𝑥𝑥 + 2)2 ∄ 𝑥𝑥 ∈ 𝑅𝑅
46 𝑥𝑥2+ �√2 − √3�𝑥𝑥 − √6 = 0 𝑥𝑥1= −√2, 𝑥𝑥2= √3
47 𝑥𝑥 3
2+ 3𝑥𝑥1 + 3 = 0 𝑥𝑥1=−9 − 3√5
2 , 𝑥𝑥2=−9 + 3√5 2 48 𝑥𝑥2−1
2 + 1 6 𝑥𝑥 = −
1
4 𝑥𝑥1=−1 − √3712 , 𝑥𝑥2=−1 + √3712
49 𝑥𝑥2+ 16 = 6√2𝑥𝑥 𝑥𝑥1= 2√2, 𝑥𝑥2= 4√2
50 4√5𝑥𝑥 − 1 = 4𝑥𝑥2 𝑥𝑥1=√5 − 2
2 , 𝑥𝑥2=√5 + 2 2
51 𝑥𝑥2− 4√3𝑥𝑥 + 12 = 0 𝑥𝑥1= 𝑥𝑥2= 2√3
52 𝑥𝑥 + √5 = �2𝑥𝑥 − √5��𝑥𝑥 + √5� 𝑥𝑥1= −√5, 𝑥𝑥2=1 + √5 2 53 �𝑥𝑥 +1
2�
2
= �3 2 − 2𝑥𝑥�
2
𝑥𝑥1= 2, 𝑥𝑥2=1 3
54 𝑥𝑥�𝑥𝑥 + √7� = 14 𝑥𝑥1= −2√7, 𝑥𝑥2= √7
Algebra
Equazioni di secondo grado
55 1
3(3 − 𝑥𝑥) +𝑥𝑥2− 1 6 −
2
3 = 0 𝑥𝑥1= 𝑥𝑥2= 1
56 2√3𝑥𝑥 = 𝑥𝑥2 + 2 𝑥𝑥1= √3 − 1, 𝑥𝑥2= √3 + 1
equazioni di secondo grado frazionarie
57 2
𝑥𝑥 = 𝑥𝑥
2 𝑥𝑥1= −2, 𝑥𝑥2= 2
58 𝑥𝑥 =1
𝑥𝑥 𝑥𝑥1= −1, 𝑥𝑥2= 1
59 √3
𝑥𝑥 = 𝑥𝑥
√27 𝑥𝑥1= −3, 𝑥𝑥2= 3
60 𝑥𝑥 − 1 = 9
𝑥𝑥 − 1 𝑥𝑥1= −2, 𝑥𝑥2= 4
61 − 2
𝑥𝑥 + 3 = 1
𝑥𝑥2 ∄ 𝑥𝑥 ∈ 𝑅𝑅
62 1
𝑥𝑥2 = 2
𝑥𝑥 + 3 𝑥𝑥1= −1, 𝑥𝑥2=
3 2
63 2
𝑥𝑥2+ 1 =
1 − 𝑥𝑥2
𝑥𝑥2+ 1 𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖
64 3
𝑥𝑥 − 1 = 2𝑥𝑥
𝑥𝑥 + 1 𝑥𝑥1= −
1
2 , 𝑥𝑥2= 3
65 3
𝑥𝑥(𝑥𝑥 − 2) =
4𝑥𝑥 − 2
𝑥𝑥 𝑥𝑥1=5 − √214 , 𝑥𝑥2=5 + √21
4
66 4
3 + 1 𝑥𝑥 − 1 =
1 + 𝑥𝑥 𝑥𝑥 − 1 −
𝑥𝑥
𝑥𝑥 + 1 𝑥𝑥1= −
1
2 , 𝑥𝑥2= 2
67 1
𝑥𝑥2 = 2 − 𝑥𝑥
𝑥𝑥 𝑥𝑥1= 𝑥𝑥2= 1
68 𝑥𝑥 + 3 𝑥𝑥 −
1
𝑥𝑥2 = −1
𝑥𝑥 𝑥𝑥1= −2 − √5 , 𝑥𝑥2= −2 + √5
69 3𝑥𝑥
𝑥𝑥 + 1 +
𝑥𝑥2
2𝑥𝑥2+ 𝑥𝑥 − 1 = 2𝑥𝑥
1 − 2𝑥𝑥 𝑥𝑥1= 0, 𝑥𝑥2=
1 9 70 11 − 3𝑥𝑥
4(𝑥𝑥 − 1) = 1 + 𝑥𝑥 𝑥𝑥2− 1 −
1
𝑥𝑥 + 1 𝑥𝑥1= −13 , 𝑥𝑥2= 3
71 1
𝑥𝑥2− 1 + 𝑥𝑥 + 1 𝑥𝑥 − 1 =
1 − 𝑥𝑥
𝑥𝑥 + 1 ∄ 𝑥𝑥 ∈ 𝑅𝑅
72 2
𝑥𝑥 + 1 + 𝑥𝑥 1 − 𝑥𝑥 =
8
1 − 𝑥𝑥2 𝑥𝑥1= −2, 𝑥𝑥2= 3
Algebra
Equazioni di secondo grado
73 3𝑥𝑥 + 2 𝑥𝑥2+ 2𝑥𝑥 +
1 𝑥𝑥 =
𝑥𝑥 + 1
𝑥𝑥 + 2 𝑥𝑥1= −1, 𝑥𝑥2= 4
74 2
𝑥𝑥 − 2𝑥𝑥 𝑥𝑥 + 1 =
2 − 𝑥𝑥
𝑥𝑥 𝑥𝑥1= 1, 𝑥𝑥2= 0 𝑖𝑖𝑛𝑛𝑖𝑖 𝑖𝑖𝑎𝑎𝑎𝑎𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑎𝑎𝑖𝑖𝑎𝑎𝑖𝑖
75 𝑥𝑥2− 11
𝑥𝑥2+ 2𝑥𝑥 − 3 + 𝑥𝑥 𝑥𝑥 − 1 =
𝑥𝑥 + 1
𝑥𝑥 + 3 𝑥𝑥1= −5, 𝑥𝑥2= 2
equazioni di secondo grado di vario tipo
76 4𝑥𝑥(2 − 𝑥𝑥) + (𝑥𝑥 − 2) = −11 𝑥𝑥1= −3, 𝑥𝑥2= 3
77 �√3 − 2𝑥𝑥�2 = �𝑥𝑥 + √3�2 𝑥𝑥1= 0, 𝑥𝑥2= 2√3
78 𝑥𝑥�𝑥𝑥 + √7� = 14 𝑥𝑥1= −2√7, 𝑥𝑥2= √7
79 4 + (1 + 2𝑥𝑥)2 = 0 ∄ 𝑥𝑥 ∈ 𝑅𝑅
80 1
2(𝑥𝑥 − 1) + 𝑥𝑥 = (𝑥𝑥 + 1)(𝑥𝑥 − 2) 𝑥𝑥1= −1
2 , 𝑥𝑥2= 3 81 (2𝑥𝑥 − 1)2+ 4(𝑥𝑥 − 2)(𝑥𝑥 + 2) = −18 ∄ 𝑥𝑥 ∈ 𝑅𝑅
82 1
3(3 − 𝑥𝑥) +𝑥𝑥2− 1 6 −
2
3 = 0 𝑥𝑥1= 𝑥𝑥2= 1
83 √2(2𝑥𝑥 + 1) + �𝑥𝑥 − √2�2 = 𝑥𝑥 + 4 𝑥𝑥1= 1 − √2, 𝑥𝑥2= √2
84 2√3𝑥𝑥 = 𝑥𝑥2 + 2 𝑥𝑥1= √3 − 1, 𝑥𝑥2= √3 + 1
85 1
𝑥𝑥 + 1 + 1 12 =
1
1 − 𝑥𝑥 𝑥𝑥1= −12 − √145, 𝑥𝑥2= −12 + √145
86 1
𝑥𝑥 + √3+ 1
𝑥𝑥 − √3= 3 𝑥𝑥1=1 − 2√7
3 , 𝑥𝑥2=1 + 2√7 3 87 𝑥𝑥 + 2 = 6
𝑥𝑥 + 2 + 1 𝑥𝑥1= −4, 𝑥𝑥2= 1
88 𝑥𝑥 − 5 8 −
𝑥𝑥 5 =
5
𝑥𝑥 − 10 𝑥𝑥1= −
10
3 , 𝑥𝑥2= 5
89 1
𝑥𝑥(2 − 𝑥𝑥) −
4 − 𝑥𝑥 𝑥𝑥(𝑥𝑥 + 2) =
2
4 − 𝑥𝑥2 𝑥𝑥1= 2 𝑖𝑖𝑛𝑛𝑖𝑖 𝑖𝑖𝑎𝑎𝑎𝑎𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑎𝑎𝑖𝑖𝑎𝑎𝑖𝑖, 𝑥𝑥2= 3
90 1
𝑥𝑥(𝑥𝑥 + 3) − 1 𝑥𝑥(2 − 𝑥𝑥) =
1
6𝑥𝑥 𝑥𝑥1= −1, 𝑥𝑥2= 12
Algebra
Equazioni di secondo grado
91 𝑥𝑥 + 2 𝑥𝑥 −
(2 + 3𝑥𝑥)
2(4 − 3𝑥𝑥) = 1 + 4
3𝑥𝑥2 − 4𝑥𝑥 𝑥𝑥1= −6, 𝑥𝑥2=
4
3 𝑖𝑖𝑛𝑛𝑖𝑖 𝑖𝑖𝑎𝑎𝑎𝑎𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑎𝑎𝑖𝑖𝑎𝑎𝑖𝑖
92 5
4𝑥𝑥 − 9 4 =
𝑥𝑥 − 3
𝑥𝑥 + 1 𝑥𝑥1= −
5
13 , 𝑥𝑥2= 1
93 𝑥𝑥
𝑥𝑥 − 6 − 1 2 =
𝑥𝑥 6 +
𝑥𝑥 + 6
6 − 𝑥𝑥 𝑥𝑥1= −3, 𝑥𝑥2= 18
94 4
(𝑥𝑥 − 2)2+ 3 = 3𝑥𝑥
2 − 𝑥𝑥 ∄ 𝑥𝑥 ∈ 𝑅𝑅
95 1
3𝑥𝑥 − 𝑥𝑥2− 1 6𝑥𝑥 =
1
2𝑥𝑥 − 𝑥𝑥2 ∄ 𝑥𝑥 ∈ 𝑅𝑅
96 𝑥𝑥 − √3
𝑥𝑥√3 − 1= 2√3 3𝑥𝑥2− 1 −
𝑥𝑥
𝑥𝑥√3 + 1 𝑥𝑥1= −
√3
2 , 𝑥𝑥2= √3
97 4
(𝑥𝑥 − 2)2− 3
𝑥𝑥2 = 5
4𝑥𝑥 − 2𝑥𝑥2 𝑥𝑥1=−7 − √2177 , 𝑥𝑥2=−7 + √217
7
98 5
2𝑥𝑥 + 2 + 1 2𝑥𝑥 − 2 =
3𝑥𝑥 + 2
𝑥𝑥2+ 𝑥𝑥 + 1 𝑥𝑥1= 0, 𝑥𝑥2= 4
99 5
6 + 2𝑥𝑥 − 1 𝑥𝑥2− 3𝑥𝑥 =
5
9 − 𝑥𝑥2 𝑥𝑥1= −
3
5 , 𝑥𝑥2= 2
100 2
(𝑥𝑥 − 1)2− �𝑥𝑥 − 1
𝑥𝑥 − 1� �𝑥𝑥 − 1
𝑥𝑥 + 1� + �𝑥𝑥 − 1 𝑥𝑥 − 1�
2
= 0 𝑥𝑥1= 1 − √3, 𝑥𝑥2= 1 + √3
101 1
𝑥𝑥 − 5 − 1 4 − 𝑥𝑥 =
2 𝑥𝑥 − 4 +
1
𝑥𝑥 − 3 𝑥𝑥1= 5 − √2, 𝑥𝑥2= 5 + √2
102 𝑥𝑥 + 3 𝑥𝑥 + 1 +
𝑥𝑥 + 5 𝑥𝑥 + 2 =
2𝑥𝑥 + 2
𝑥𝑥 𝑥𝑥1= −
4
3 , 𝑥𝑥2= 1
103 𝑥𝑥2
200 − 𝑥𝑥2 =1
7 𝑥𝑥1= −5, 𝑥𝑥2= 5
104 2(𝑥𝑥 − 1) 𝑥𝑥 + 1 +
(𝑥𝑥 + 1)
4(𝑥𝑥 − 1) = 3 𝑥𝑥1=−7 − 4√73 , 𝑥𝑥2=−7 + 4√7
3
105 𝑥𝑥 − 2 3 − 𝑥𝑥 +
2𝑥𝑥 + 9 𝑥𝑥2− 9 =
2𝑥𝑥 + 1
𝑥𝑥 + 3 𝑥𝑥1= 1 − √7, 𝑥𝑥2= 1 + √7
106 5𝑥𝑥2− 5𝑥𝑥 − 28 𝑥𝑥2− 𝑥𝑥 − 6 =
4 𝑥𝑥 + 2 −
2
𝑥𝑥 − 3 𝑥𝑥1= −1, 𝑥𝑥2=
12 5