数学
2(x^2-7/2x)=-62(x^2-7/2x+49/16)=-6+49/82(x-7/4)^2=1/8(x-7/4)^2=1/16x-7/4=+1/4x1=2x-7/4=-1/4x2=3/2
(2x-3)(x-2)=0
