（2又5分之2×3.75÷1又5分之7）+（15分之4×1又5分之2÷15分之4）简便计算,实在不行可硬算

[ (2+ 2/5) X 3.75 / (1+ 5/7) ] + [ 4/15 X (1+ 2/5) / (4/15) ]
= [ (3+ 3/4) X (12/5) / (12/7) ] + [ (7/5) X (4/15) / (4/15) ]
= [ 15/4 X 12/5 X 7/12 ] + 7/5
= ( 15/4 X 7/5 ) + 7/5
= ( 15/4 + 4/4 ) X 7/5
= 19/4 X 7/5
= 7 X 19/20
= 7 X (1 - 1/20)
= 7 - 0.35
= 6.65

（2又5分之2×3.75÷1又5分之7）+（15分之4×1又5分之2÷15分之4）

=(2+2/5) ×3/8 ×5/12+4/15 × 7/5 ×15/4

= 3/4×5/12 + 2/5 ×&...