(2.7减4.25乘五分之二)除以2.8再除以七顷早分之四=(2.7-4.25×0.4）÷2.8÷4/7=（2.7-1.7）÷2.8÷4/7=1÷28/10÷4/7=5/14×7/4=5/8=0.625 1.25＋1又四分之一×7.4＋125％÷八分之五=1.25+1.25×7.4+1.25×8/燃乎型5=1.25×（皮猜1+7.4+1.6）=1.25×10=12.5
