解析:
运用乘法交换律和乘法分配律进行简便计算:
5/12×19/24+19/12×7/24
=5/12×19/24+7/12×19/24 (交换19和7的位置)
=(5/12+7/12)×19/24 (提取公因数19/24)
=1×19/24
=19/24
解:
5/12×19/24+19/12×7/24
=19/12×5/24+19/12×7/24
=19/12 x (5/24+7/24)
=19/12 x 12/24
=19/24
=5/12*19/24+19/12*7/24
=5/24*19/12+19/12*7/24
=(5/24+7/24)*19/12
=12/24*19/12
=19/24
解:5/12x19/24+19/12x7/24
=19/12x5/24+19/12x7/24
=19/12x(5/24+7/24)
=19/12x12/24
=12/12x19/24
=19/24
原式=19/24*(5/12+7/12)
=19/24*1
=19/24