解方程 (3x+1)(3x-1)=(x+2)(9x-4) 2(x-3)(x-2)-(x+3)²=(x-1)(x+1)
解方程 (3x+1)(3x-1)=(x+2)(9x-4) 2(x-3)(x-2)-(x+3)²=(x-1)(x+1)
(3x+1)(3x-1)=9x的平方-1=(x+2)(9x-4)=9x的平方+14x-8
14x-7=0,所以x=2分之1
2(x-3)(x-2)-(x+3)的平方=2x的平方-10x+12-x的平方-6x-9=x的平方-16x+3
(x-1)(x+1)=x的平方-1=x的平方-16x+3
所以16x=4,x=4分之1
9x²-1=9x²+14x-8
-14x=-7
x=1/2
2x²-10x+12-x²-6x-9=x²-1
-16x=-4
x=1/4
(3x+1)(3x-1)=(x+2)(9x-4)
9x²-1=9x²+18x-4x-8
-14x=-7
x=1/2
2(x-3)(x-2)-(x+3)²=(x-1)(x+1)
2x²-10x+12-x²-6x-9=x²-1
-16x=-4
x=1/4
是两个方程吧
(1) (3x+1)(3x-1)=(x+2)(9x-4)
9x^2-1=9x^2+14x-8
14x=7
x=1/2
(2)2(x-3)(x-2)-(x+3)²=(x-1)(x+1)
2(x^2-5x+6)-(x^2+6x+9)=x^2-1
2x^2-10x+12-x^2-6x-9=x^2-1
-16x=-4
x=1/4
(3x+1)(3x-1)=(x+2)(9x-4) 9x^2-1 = 9x^2+14x-8-14x=-7x=1/22(x-3)(x-2)-(x+3)²=(x-1)(x+1)2(x^2-5x+6)-(x^2+6x+9)=x^2-12x^2-10x+12-x^2-6x-9=x^2-1x^2-16x+3=x^2-1-16x=-4x=1/4