用平方差公式公式:1、(3x-1/2)(-1/2-3x)(-1/4-9x²)

1个回答

  • 1、(3x-1/2)(-1/2-3x)(-1/4-9x²)=-(3x-1/2)(3x+1/2)(-1/4-9x²)=(3x-1/2)(3x+1/2)(1/4+9x²)=(9x²)²-(1/4)²

    1、(x+3)(x-3)-x(x-2)=x²-9-x²+2x=2x-9=-1

    2、(3x²-2y²)(-2y²-3x²)+3(x²-y²)(x²+y²)=-(3x²)²+(2y²)²+3(x²)²-3(y²)²=(y²)²-6(x²)²=10

    3、(1-2a)(1+2a)(1+4a²)(1+16a四次方)=(1-4a²)(1+4a²)(1+16a四次方)=(1-16a四次方)(1+16a四次方)=1-256a八次方=0

    之后的计算类似,你应该学会自己多练习练习,这样才会进步!