(-421)×(-1/4)-0.25×(-7 1/2)-28.5×25%

问题描述:

(-421)×(-1/4)-0.25×(-7 1/2)-28.5×25%

(-421)×(-1/4)-0.25×(-7 1/2)-28.5×25%
=421x0.25+7.5x0.25-28.5x0.25
=(421+7.5-28.5)x0.25
=400x0.25
=100