题目先化简,再求值:(x−2)2−10x(x−1)+(3x−1)(3x+1)\left(x-2\right)^{2}-10x\left(x-1\right)+\left(3x-1\right)\left(3x+1\right)(x−2)2−10x(x−1)+(3x−1)(3x+1),其x=−12x=-\frac{1}{2}x=−21.知识点：单项式乘多项式章节：数与式 / 整式
