我想知道(51+42)x4有簡便運算嗎

我想知道(51+42)x4有簡便運算嗎



(51+42)x4
=93*4
=(100-7)*4
=400-28
=372



4分之5-7分之2-7分之5的簡便算灋
6分之7-(3分之2+6分之1)
1-4分之3+4分之1
8分之5+4分之1-2分之1-4分之1


5/4-2/7-5/7
=5/4-(2/7+5/7)
=1又1/4-1
=1/4
7/6-(2/3+1/6)
=7/6-1/6-2/3
=1-2/3
=1/3
1-3/4+1/4
=1-(3/4-1/4)
=1-1/2
=1/2
5/8+1/4-1/2-1/4
=(5/8-1/2)+(1/4-1/4)
=5/8-4/8
=1/8