基本次の2次方程式を、因数分解を利用して解きなさい。
(1)(x−2)(x−5)=0 | (11)x2+3x−10=0 |
(2)(x+3)(x−7)=0 | (12)x2−2x−15=0 |
(3)(x+4)(x+6)=0 | (13)x2+6x+9=0 |
(4)x(x−9)=0 | (14)x2−10x+25=0 |
(5)x2+5x+6=0 | (15)x2+4x+4=0 |
(6)x2+7x+12=0 | (16)x2−9=0 |
(7)x2−5x+4=0 | (17)x2−49=0 |
(8)x2−8x+15=0 | (18)x2−3x=0 |
(9)x2+2x−8=0 | (19)x2+8x=0 |
(10)x2−x−12=0 | (20)x2−16=0 |
標準次の2次方程式を、因数分解を利用して解きなさい。
(1)x2+9x+20=0 | (11)x2+2x−35=0 |
(2)x2+11x+24=0 | (12)x2−9x−22=0 |
(3)x2−7x+10=0 | (13)x2+12x+36=0 |
(4)x2−11x+30=0 | (14)x2−14x+49=0 |
(5)x2+x−20=0 | (15)x2−64=0 |
(6)x2−4x−21=0 | (16)x2−121=0 |
(7)x2+5x−24=0 | (17)x2+10x=0 |
(8)x2−6x−16=0 | (18)2x2−6x=0 |
(9)x2+13x+36=0 | (19)3x2+12x=0 |
(10)x2−13x+42=0 | (20)x2−100=0 |
整理して解く次の2次方程式を解きなさい。(式を整理してから因数分解する。)
(1)x2=3x | (11)x2=81 |
(2)x2=−5x | (12)(x+2)(x−3)=6 |
(3)x2+4x=12 | (13)(x−1)(x+5)=−5 |
(4)x2−3x=18 | (14)(x+3)2=16 |
(5)x2=x+6 | (15)(x−2)2=9 |
(6)x2=2x+15 | (16)(x−5)2=1 |
(7)x2+6=5x | (17)x(x+2)=15 |
(8)x2+20=9x | (18)x(x−6)=−8 |
(9)x2−8=2x | (19)(x+1)(x+6)=14 |
(10)x2=25 | (20)(x−3)(x+2)=14 |
発展次の2次方程式を解きなさい。(共通因数でくくる・式を整理するなど工夫する。)
(1)3x2−27=0 | (11)(x+3)(x−1)=x+9 |
(2)2x2−50=0 | (12)(x−4)2=x−4 |
(3)4x2−8x=0 | (13)x2+(x+1)2=41 |
(4)5x2+15x=0 | (14)(x+1)2+(x+2)2=13 |
(5)2x2+10x+12=0 | (15)(x+5)2=10x+41 |
(6)3x2−15x+18=0 | (16)x(x+1)=2(x+6) |
(7)2x2−4x−30=0 | (17)(x+4)(x−4)=6x |
(8)−x2+4x+5=0 | (18)x(x+1)=56 |
(9)x2−2x+1=0 | (19)x2=3x+40 |
(10)(x+2)(x−2)=3x | (20)(x+3)2=49 |
(1)x=5, 2
(2)x=7, −3
(3)x=−4, −6
(4)x=9, 0
(5)x=−2, −3
(6)x=−3, −4
(7)x=4, 1
(8)x=5, 3
(9)x=2, −4
(10)x=4, −3
(11)x=2, −5
(12)x=5, −3
(13)x=−3(重解)
(14)x=5(重解)
(15)x=−2(重解)
(16)x=±3
(17)x=±7
(18)x=3, 0
(19)x=0, −8
(20)x=±4
(1)x=−4, −5
(2)x=−3, −8
(3)x=5, 2
(4)x=6, 5
(5)x=4, −5
(6)x=7, −3
(7)x=3, −8
(8)x=8, −2
(9)x=−4, −9
(10)x=7, 6
(11)x=5, −7
(12)x=11, −2
(13)x=−6(重解)
(14)x=7(重解)
(15)x=±8
(16)x=±11
(17)x=0, −10
(18)x=3, 0
(19)x=0, −4
(20)x=±10
(1)x=3, 0
(2)x=0, −5
(3)x=2, −6
(4)x=6, −3
(5)x=3, −2
(6)x=5, −3
(7)x=3, 2
(8)x=5, 4
(9)x=4, −2
(10)x=±5
(11)x=±9
(12)x=4, −3
(13)x=0, −4
(14)x=1, −7
(15)x=5, −1
(16)x=6, 4
(17)x=3, −5
(18)x=4, 2
(19)x=1, −8
(20)x=5, −4
(1)x=±3
(2)x=±5
(3)x=2, 0
(4)x=0, −3
(5)x=−2, −3
(6)x=3, 2
(7)x=5, −3
(8)x=5, −1
(9)x=1(重解)
(10)x=4, −1
(11)x=3, −4
(12)x=5, 4
(13)x=4, −5
(14)x=1, −4
(15)x=±4
(16)x=4, −3
(17)x=8, −2
(18)x=7, −8
(19)x=8, −5
(20)x=4, −10