(1-2x)²=1,9(3x+1)²=64,这两个怎样解X?
问题描述:
(1-2x)²=1,9(3x+1)²=64,这两个怎样解X?
答
由(1-2x)^2=1得(1-2x)^2-1=(1-2x)^2-1^2=(1-2x-1)(1-2x+1)=-2x(2-2x)=0所以X=0或2-2x=0即x=0或x=1由9(3x+1)²=64得9(3x+1)²-64=[3^2(3x+1)^2]-64=[3(3x+1)]^2-8^2=(9x+3)^2-8^2=(9x+3-8)(9x+3+8)=(9x-5)(9x...