①（3/7+2/3-10%）×21 =3*3+2*7-2.1=20.9 (2)3/5×53％+60％×0.47 =60%(53%+47%) =60%=0.6 ③3/4-（20％+1/3）×4.5=3/4-(0.9+1.5)=0.75-2.4=-1.65看不懂，你告诉哪个是可以简算的就可以了

1. ①（3/7+2/3-10%）×21
2. =3*3+2*7-2.1
3. =20.9
4. (2)3/5×53％+60％×0.47
5. =60%(53%+47%)
6. =60%=0.6
7. ③3/4-（20％+1/3）×4.5
8. =3/4-(0.9+1.5)
9. =0.75-2.4
10. =-1.65