(急速 现1小时内)用恰当的方法解方程:(1)x^2-4x+3=0 (2)(x-2)^2=256(3)x^2-3x+1==0 (4)x^2-2x-3=0(5)(2t+3)^2=3(2t+3) (6)(3-y)^2+y^2=9(7)(1+根号2)x^2-(1-根号2)x=0(8)2x^2-8x=7(9)(x+5)^2-2(x+5)-8=0
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![(急速 现1小时内)用恰当的方法解方程:(1)x^2-4x+3=0 (2)(x-2)^2=256(3)x^2-3x+1==0 (4)x^2-2x-3=0(5)(2t+3)^2=3(2t+3) (6)(3-y)^2+y^2=9(7)(1+根号2)x^2-(1-根号2)x=0(8)2x^2-8x=7(9)(x+5)^2-2(x+5)-8=0](/uploads/image/z/207770-50-0.jpg?t=%EF%BC%88%E6%80%A5%E9%80%9F+%E7%8E%B01%E5%B0%8F%E6%97%B6%E5%86%85%EF%BC%89%E7%94%A8%E6%81%B0%E5%BD%93%E7%9A%84%E6%96%B9%E6%B3%95%E8%A7%A3%E6%96%B9%E7%A8%8B%EF%BC%9A%EF%BC%881%EF%BC%89x%5E2-4x%2B3%3D0+%EF%BC%882%29%28x-2%29%5E2%3D256%283%EF%BC%89x%5E2-3x%2B1%3D%3D0+%EF%BC%884%EF%BC%89x%5E2-2x-3%3D0%285%29%282t%2B3%29%5E2%3D3%282t%2B3%29+%286%29%283-y%29%5E2%2By%5E2%3D9%287%29%281%2B%E6%A0%B9%E5%8F%B72%EF%BC%89x%5E2-%281-%E6%A0%B9%E5%8F%B72%29x%3D0%288%292x%5E2-8x%3D7%289%29%28x%2B5%29%5E2-2%28x%2B5%29-8%3D0)
(急速 现1小时内)用恰当的方法解方程:(1)x^2-4x+3=0 (2)(x-2)^2=256(3)x^2-3x+1==0 (4)x^2-2x-3=0(5)(2t+3)^2=3(2t+3) (6)(3-y)^2+y^2=9(7)(1+根号2)x^2-(1-根号2)x=0(8)2x^2-8x=7(9)(x+5)^2-2(x+5)-8=0
(急速 现1小时内)用恰当的方法解方程:(1)x^2-4x+3=0 (2)(x-2)^2=256
(3)x^2-3x+1==0 (4)x^2-2x-3=0
(5)(2t+3)^2=3(2t+3) (6)(3-y)^2+y^2=9
(7)(1+根号2)x^2-(1-根号2)x=0
(8)2x^2-8x=7
(9)(x+5)^2-2(x+5)-8=0
(急速 现1小时内)用恰当的方法解方程:(1)x^2-4x+3=0 (2)(x-2)^2=256(3)x^2-3x+1==0 (4)x^2-2x-3=0(5)(2t+3)^2=3(2t+3) (6)(3-y)^2+y^2=9(7)(1+根号2)x^2-(1-根号2)x=0(8)2x^2-8x=7(9)(x+5)^2-2(x+5)-8=0
1、x^2-4x+3=0 变形得(x-1)(x-3)=0 解得:x=1、x=3
2、(x-2)^2=256 x-2=16或者x-2=-16 解得:x=18、x=-14
3、x^2-3x+1=0 用公式法,x=(-b+根号b方-4ac)/2=(3+根号5)/2
x=(-b-根号b方-4ac)/2=(3-根号5)/2
(4)x^2-2x-3=0 (x-3)(x-1)=0 解得:x=3、x=-1
(5)(2t+3)^2=3(2t+3) 设2t+3=x,则原方程变为:x^2=3x 解之得:x=0或者x=3即2t+3=0或者2t+3=3 解得:t=-1.5、t=0
(6)(3-y)^2+y^2=9 去括号,合并同类项后得:2y^2-6y=0 解得:y=0、y=3