(x-8)(-20x+400)=640

问题描述:

(x-8)(-20x+400)=640

X=4或X=24步骤(X-8)*-20(X-20)=640(X-8)*(X-20)=-32X^2-28X+160=-32X^2-28X+192=0(X-12)(X-16)=0X=12或X=16 好吧 丢人了不小心搞错了不好意思哈