能简算的要简算：（27+23-10%）×2135×53%+60%×0.47234-（20%+13）×4.5．

Question

能简算的要简算：
（(2)/(7)+(2)/(3)-10%）×21         (3)/(5)×53%+60%×0.47        2(3)/(4)-（20%+(1)/(3)）×4.5．

Answer 1

（(2)/(7)+(2)/(3)-10%）×21 
=(2)/(7)×21+(2)/(3)×21-0.1×21
=6+14-2.1
=17.9；
(3)/(5)×53%+60%×0.47
=0.6×0.53+0.6×0.47
=0.6×（0.53+0.47）
=0.6×1
=0.6；
2(3)/(4)-（20%+(1)/(3)）×4.5
=2(3)/(4)-（(1)/(5)+(1)/(3)）×4.5
=2(3)/(4)-(8)/(15)×4.5
=2(3)/(4)-(12)/(5)
=(7)/(20)．