3(x+2)²=x²-4怎么解?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/05 11:16:49
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3(x+2)²=x²-4怎么解?
3(x+2)²=x²-4怎么解?
3(x+2)²=x²-4怎么解?
3(x+2)²=(x+2)(x-2)
3(x+2)²-(x+2)(x-2)=0
(x+2)[3(x+2)-(x-2)]=0
(x+2)(2x+8)=0
x=-2,x=-4
解由3(x+2)^2=x^2-4
得3(x+2)^2=(x-2)(x+2)
即3(x+2)^2-(x-2)(x+2)=0
即(x+2)(3(x+2)-(x-2))=0
即(x+2)(2x+8)=0
得x+2=0或2x+8=0
解得x=-2或x=-4.
3(x+2)²=x²-4
3x²+12x+12=x²-4
2x²+12x+16=0
x²+6x+8=0
(x+3)²=1
x=-3-1=-4
或x=-3+1=-2