令m%=x则30%+70%*m%+70%(1-m%)m%=43.3%为30%+70%x+70%(1-x)x=43.3% 70%x+70%x-70%x=13.3% 70%（2x-x）=13.3% 2x-x=0.19 (x-1)=0.81 x1=1.9 x2=0.1 则m%=190%或10%