[-270]乘以4分之1+0.25乘以21.5+[-8又2分之1]乘以[-百分之25]=

问题描述:

[-270]乘以4分之1+0.25乘以21.5+[-8又2分之1]乘以[-百分之25]=

[-270]乘以4分之1+0.25乘以21.5+[-8又2分之1]乘以[-百分之25] =(-270)X1/4+0.25X21.5+(-8又1/2)X(-25/100) =0.25X21.5-270X1/4+8.5X25/100 =0.25X21.5-270X0.25+8.5X0.25 =0.25X(21.5+8.5-270) =0.25X(-240) =-60 ...