2/3-5/6×3/10+3/2
=2/3-1/4+3/2
=48/12-3/12+18/12
=21/4
7/4÷(2/3+1/2)×4/5
=(7/4×4/5)÷(2/3+1/2)
=7/5÷(4/6+3/6)
=7/5÷7/6
=7/5×6/7
=6/5第一个那是简算么？！！你好：同学！第1题不能再简算了