![](https://static.youtibao.com/asksite/comm/h5/images/m_q_title.png)
[单选题]
以下异分母计算中,正确的是()
A.1/3+1/4=1/(3+4)=1/7
B.1/3+1/4=(1+1)/(3+4)=2/7
C.1/3-1/4=1/(4-3)=1/1=1
D.1/3-1/4=4/12-3/12=1/12
![](https://static.youtibao.com/asksite/comm/h5/images/m_q_a.png)
D、1/3-1/4=4/12-3/12=1/12
![](https://static.youtibao.com/asksite/comm/h5/images/solist_ts.png)
A.1/3+1/4=1/(3+4)=1/7
B.1/3+1/4=(1+1)/(3+4)=2/7
C.1/3-1/4=1/(4-3)=1/1=1
D.1/3-1/4=4/12-3/12=1/12
D、1/3-1/4=4/12-3/12=1/12
A.1000人
B.(400+200)/2人
C.(400+300+100+200)/4人
D.400+300×3/4+100×1/2+200×1/4人