33又1/3*(-2.5)*(-7)*4*(-0.3)
=-100/3*0.3*(2.5*4)*7
=-30*10*7
=-2100
-13*2/3-0.34*2/7+1/3*(-13)-5/7*0.34
=-13*(2/3+1/3)-0.34*(2/7+5/7)
=-13-0.34
=-13.34
某商品价格为a元,降价10%后又降价10%,销售量增,商场决定再提价20%,则提价后这种商品价格为?
a×(1-10%)×(1-10%)×(1+20%)
=a× 81%×120%
=0.972a元
49又24/25*5
=(50-1/25)*5
=50*5-1/25*5
=250-1/5
=249.8