层等下列各题 （用简便方法计算）975-147-23 134x8+8x66 125x64 365x99 3000/125/8 99x25 6x75+6x2525x24 12x15 全部用简便算法层等算.快,求求你们了.
问题描述：
层等下列各题 （用简便方法计算）
975-147-23 134x8+8x66 125x64 365x99 3000/125/8 99x25 6x75+6x25
25x24 12x15 全部用简便算法层等算.快,求求你们了.
答
975-147-23
=975-(147+23)
=975-170
=805
134x8+8x66
=8x(134+66)
=8x200
=1600
125x64
=125x8x8
=1000x8
=8000
365x99
=365x(100-1)
=36500-365
=36135
3000/125/8
=3000/(125x8)
=3000/1000
=3
99x25
=(100-1)x25
=2500-25
=2475
6x75+6x25
25x24
=25x4x6
=100x6
=600
12x15
=(10+2)x15
=150+30
=180