简便方法计算．(37+328)×7；35×63%+75×63%；5.2×14+1.8×0.25．

Question

简便方法计算． ((3)/(7) +(3)/(28) )×7 ；

(3)/(5) ×63%+(7)/(5) ×63% ；

5.2×(1)/(4) +1.8×0.25 ．

Answer 1

（1） ((3)/(7) +(3)/(28) )×7
= (3)/(7) ×7+ (3)/(28) ×7
=3+ (3)/(4)
=3 (3)/(4) ；

（2） (3)/(5) ×63%+(7)/(5) ×63%
=（ (3)/(5) + (7)/(5) ）×63%
=2×0.63
=1.26；

（3） 5.2×(1)/(4) +1.8×0.25
=（5.2+1.8）×0.25
=7×0.25
=1.75．