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二次方程式 100問 (1)　１〜５０

組　　番名前　　　　　　　　　
① 平方根の考え方を使って解こう
1x² = 9
2x² = 25
3x² = 7
4x² − 16 = 0
5x² − 5 = 0
64x² = 9
79x² = 16
82x² = 18
93x² − 27 = 0
105x² − 20 = 0
112x² − 6 = 0
123x² − 15 = 0
13(x + 1)² = 4
14(x − 3)² = 16
15(x + 2)² = 9
16(x − 5)² = 3
17(x + 4)² = 5
18(x − 1)² = 12
19(x + 3)² − 25 = 0
20(x − 2)² − 8 = 0
② 因数分解を使って解こう
21x² − 3x + 2 = 0
22x² − 5x + 6 = 0
23x² + 3x + 2 = 0
24x² + 2x − 3 = 0
25x² + 2x − 8 = 0
26x² − 8x + 15 = 0
27x² + 7x + 10 = 0
28x² − 3x − 4 = 0
29x² − 4x − 21 = 0
30x² − 11x + 30 = 0
31x² − 1 = 0
32x² − 4 = 0
33x² − 9 = 0
34x² − 4x = 0
35x² + 3x = 0
36x² − 4x − 12 = 0
37x² + 10x + 24 = 0
38x² − 9x + 14 = 0
39x² + 7x − 8 = 0
40x² − 8x + 16 = 0
41x² + 6x + 9 = 0
42x² + 2x − 35 = 0
43x² − 8x − 9 = 0
44x² − 11x + 24 = 0
45x² − 36 = 0
46x² − 8x − 20 = 0
47x² + 9x + 14 = 0
48x² − 13x + 12 = 0
49x² + 7x − 18 = 0
50x² − 13x + 42 = 0

二次方程式 100問 (2)　５１〜１００

組　　番名前　　　　　　　　　
③ 因数分解（x² の係数に注意）
512x² + 7x + 3 = 0
522x² − 5x + 2 = 0
533x² + 7x + 2 = 0
544x² + 4x − 3 = 0
553x² + x − 2 = 0
562x² + x − 15 = 0
574x² − 3x − 1 = 0
586x² + x − 2 = 0
594x² + 4x + 1 = 0
605x² + 9x − 2 = 0
616x² − 7x − 3 = 0
626x² − 11x − 2 = 0
632x² + 5x − 7 = 0
649x² − 1 = 0
654x² + 5x − 6 = 0
666x² − 7x + 2 = 0
675x² − 13x − 6 = 0
686x² + 11x + 4 = 0
698x² − 10x − 3 = 0
706x² + 13x − 5 = 0
④ 解の公式を使って解こう
71x² + 3x + 1 = 0
72x² − 5x + 3 = 0
73x² + x − 1 = 0
74x² − 3x − 1 = 0
75x² + 5x + 2 = 0
762x² + 3x − 1 = 0
772x² − 5x + 1 = 0
783x² + 5x + 1 = 0
79x² − 7x + 2 = 0
802x² + 4x − 1 = 0
81x² + 2x − 4 = 0
82x² − 4x + 1 = 0
83x² + 6x + 3 = 0
843x² − 4x − 1 = 0
852x² − 6x + 1 = 0
86x² − x − 3 = 0
875x² + 3x − 1 = 0
88x² + 8x + 2 = 0
894x² − 2x − 1 = 0
90x² − 9x + 4 = 0
⑤ 式を整理してから解こう
91(x + 1)(x + 3) = 8
92x(x − 4) = 12
93(x − 2)(x + 5) = 8
94(x + 3)² = 2x + 9
95(x − 1)(x + 1) = 3x + 9
96x² + 2x = 3(x + 2)
97(2x + 1)(x − 2) = x² + 2
98(x + 4)(x − 4) = 6x − 9
99(x − 3)² = 4(x − 3)
100(x + 1)² + (x + 2)² = 25

二次方程式 100問 解答

1x = ±3
2x = ±5
3x = ±√7
4x = ±4
5x = ±√5
6x = ±32
7x = ±43
8x = ±3
9x = ±3
10x = ±2
11x = ±√3
12x = ±√5
13x = 1, −3
14x = 7, −1
15x = 1, −5
16x = 5 ± √3
17x = −4 ± √5
18x = 1 ± 2√3
19x = 2, −8
20x = 2 ± 2√2
21x = 2, 1
22x = 3, 2
23x = −1, −2
24x = 1, −3
25x = 2, −4
26x = 5, 3
27x = −2, −5
28x = 4, −1
29x = 7, −3
30x = 6, 5
31x = ±1
32x = ±2
33x = ±3
34x = 4, 0
35x = 0, −3
36x = 6, −2
37x = −4, −6
38x = 7, 2
39x = 1, −8
40x = 4
41x = −3
42x = 5, −7
43x = 9, −1
44x = 8, 3
45x = ±6
46x = 10, −2
47x = −2, −7
48x = 12, 1
49x = 2, −9
50x = 7, 6
51x = −12, −3
52x = 2, 12
53x = −13, −2
54x = 12, −32
55x = 23, −1
56x = 52, −3
57x = 1, −14
58x = 12, −23
59x = −12
60x = 15, −2
61x = 32, −13
62x = 2, −16
63x = 1, −72
64x = ±13
65x = 34, −2
66x = 23, 12
67x = 3, −25
68x = −12, −43
69x = 32, −14
70x = 13, −52
71x = −3 ± √52
72x = 5 ± √132
73x = −1 ± √52
74x = 3 ± √132
75x = −5 ± √172
76x = −3 ± √174
77x = 5 ± √174
78x = −5 ± √136
79x = 7 ± √412
80x = −2 ± √62
81x = −1 ± √5
82x = 2 ± √3
83x = −3 ± √6
84x = 2 ± √73
85x = 3 ± √72
86x = 1 ± √132
87x = −3 ± √2910
88x = −4 ± √14
89x = 1 ± √54
90x = 9 ± √652
91x = 1, −5
92x = 6, −2
93x = 3, −6
94x = 0, −4
95x = 5, −2
96x = 3, −2
97x = 4, −1
98x = 7, −1
99x = 7, 3
100x = 2, −5