解方程:(1)4x^2-4x+1=9 (2)x^2-6x+9=(5-2x)^2 (3)4(2x+1)^2=9(2x-1)^2
解方程:(1)4x^2-4x+1=9 (2)x^2-6x+9=(5-2x)^2 (3)4(2x+1)^2=9(2x-1)^2
:(1)4x^2-4x+1=9
4x²-4x+1-9=0
4x²-4x-8=0
x²-x-2=0
﹙x-2﹚﹙x+1﹚=0
∴x=2或x=﹣1
(2)x^2-6x+9=(5-2x)^2
﹙x-3﹚²=(5-2x)^2
﹙x-3﹚²-(5-2x)^2 =0
[﹙x-3﹚+﹙5-2x)][﹙x-3﹚-(5-2x)]=0
﹙x-3+5-2x﹚﹙x-3-5+2x﹚=0
﹙﹣x+2﹚﹙3x-8﹚=0
∴x=2或x=8/3
(3)4(2x+1)^2=9(2x-1)^2
[2﹙2x+1﹚]²=[3﹙2x-1﹚]²
[2﹙2x+1﹚]²- [3﹙2x-1﹚]²=0
﹙4x+2﹚²-﹙6x-3﹚²=0
[﹙ 4x+2﹚+﹙6x-3﹚][﹙4x+2﹚-﹙6x-3﹚]=0
﹙10x-1﹚﹙﹣2x+5﹚=0
∴x=1/10或x=5/2
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4x^2-4x+1=9
x^2-x-2=0
(x-2)(x+1)=0
x1=2,x=-1
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x^2-6x+9=(5-2x)^2
3x^2-14x+16=0
(x-2)(3x-8)=0
x1=2,x2=8/3
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4(2x+1)^2=9(2x-1)^2
[2(2x+1)]^2=[3(2x-1)]^2
4x+2=6x-3或4x+2=3-6x
x=5/2或x=1/10
(1)4x^2-4x+1=9
4x^2-4x-8=0
x^2-x-2=0
(x+1)(x-2)=0
x=-1或x=2
(2)x^2-6x+9=(5-2x)^2
(x-3)^2=(5-2x)^2
x-3=5-2x或x-3=2x-5
x=8/3或x=2
(3)4(2x+1)^2=9(2x-1)^2
[2(2x+1)]^2=[3(2x-1)]^2
4x+2=6x-3或4x+2=3-6x
x=5/2或x=1/10
(1)移项,因式分解,解得x1=2,x2=-1
(2)左边为完全平方,方程可变为x-3=5-2x 或x-3=-(5-2x) 解得x1=8/3,x2=2
(3)同上题目方法,解得x1=5/2,x2=1/10