7.2乘0.25加2.8除以4
=7.2*1/4+2.8*1/4 0.25化成分数为1/4 后边除以4就等于乘以4的倒数,即1/4
=(7.2+2.8)*1/4 利用乘法分配律
=10*1/4
=2.5
7.2乘0.25加2.8除以4
=7.2*0.25+2.8*0.25
=0.25*(7.2+2.8)
=0.25*10
=2.5
不懂可追问,有帮助请采纳,谢谢!
7.2乘0.25加2.8除以4
=7.2*0.25+2.8*0.25
=(7.2+2.8)*0.25
=10*0.25
=2.5
7.2×0.25+2.8÷4
=7.2×0.25+2.8×0.25
=(7.2+2.8)×0.25
=10×0.25
=2.5
望采纳
7.2*0.25+2.8*0.25=(7.2+2.8)*0.25=2.5