1)
4X²-1 = (2x+1)(2x-1) =0
所以x= -1/2或者x=1/2
2)
9X²+6X+1 = (3x+1)² = 4
3x+1 = 2或3x +1 = -2
所以x =1/3或x = -1
4X²-1=0
解:(2x-1)(2x+1)=0
2x-1=0 或2x+1=0
x1=1/2 x2= -1/2
9X²+6X+1=4
解:(3x+1)²=4
3x+1=±2
x1=1/3 x2= -1
1.4X方-1方=0————(2X+1)(2X-1)=0
2.(3X+1)方=4