1、x(2x+1)(1-2x)-4x(x-1)(1-x),其中x=-1
x(2x+1)(1-2x)-4x(x-1)(1-x)
= x(1+2x)(1-2x)+4x(x-1)(x-1)
= x【(1-4x²)+4(x-1)²】
= x【(1-4x²)+4(x²-2x+1)】
= x【1-4x²+4x²-8x+4】
= x(5-8x)
=-1×(5+8)
=-13
2、(3a-1)²-3(2-5a+3a²),其中a=-1/3
(3a-1)²-3(2-5a+3a²)
=(3a-1)²-3(3a-2)(3a-1)
=(3a-1)【(3a-1)-3(3a-2)】
=(3a-1)(3a-1-9a+6)
=(3a-1)(-6a+5)
=(-2)×7
=-14