1. 0.7×19 4/9+2 3/4×-14+0.7×5/9+1/4×-14 2. -36×-4/9+5/6-7/12 3. 99 7/8×-13 4. -17×-3 1/17

题目

1. 0.7×19 4/9+2 3/4×-14+0.7×5/9+1/4×-14 2. -36×-4/9+5/6-7/12 3. 99 7/8×-13 4. -17×-3 1/17
1。 0.7×19 4/9+2 3/4×-14+0.7×5/9+1/4×-14
2. -36×-4/9+5/6-7/12
3. 99 7/8×-13
4. -17×-3 1/17

答案

0.7×19又4/9+2又3/4×-14+0.7×5/9+1/4×-14 =(0.7×19又4/9+0.7×5/9)-(2又3/4×14+1/4×14)=0.7×(19又4/9+5/9)-14×(2又3/4+1/4)=0.7×20-14×3=14-14×3=14×(1-3)=14×(-2)=-28-36×-4/9+5/6-7/12 =-4×(-4)+(...