33又1/3*-2.5*-7*4*-0.3= -100/3*2.5*7*4*3/10 约分,然后=-10*2.5*7*4=-700.
a*0.9*0.9=0.81a 这是2次降价后的价格.0.81a*(1+20%)=0.972a 或者是原价的97.2%.
33又1/3*-2.5*-7*4*-0.3= -100/3*2.5*7*4*3/10 约分,然后=-10*2.5*7*4=-700.
a*0.9*0.9=0.81a 这是2次降价后的价格.0.81a*(1+20%)=0.972a 或者是原价的97.2%.