1.64(2-x)的3次方=27 2.x^2-(3+x)^2=4-(3-x)^

问题描述:

1.64(2-x)的3次方=27 2.x^2-(3+x)^2=4-(3-x)^

[64(2-x)]^3=27 (x-3-x)(x+3+x)=(2-3+x)(2+3-x)
64(2-x)=3 -3(2x+3)=(-1+x)(5-x)
2-x=3/64 -6x-9=-5+x+5x-x^2
x=125/64 4=x^2
x1=2 x2=-2

1.64(2-x)的3次方=27 (2-x)^3=27/64(2-x)^3=(3/4)^32-x=3/4x=2-3/4x=5/42.x^2-(3+x)^2=4-(3-x)^2x^2+(3-x)^2-(3+x)^2=4x^2+(3-x+3+x)(3-x-3-x)=4x^2+6*(-2x)=4x^2-12x=4(x-6)^2=40x-6=±√40x=6±2√10...