Question

帮忙简便运算一下几道题。

7.48+3.17-（2.48-6.83） 7.6x7/4+17.5x6/25 1333305/2x88+880x133339/4

3.6x11.1+1.2x66.7 7.2x14.5+17x2.8 256x254/255+254x1/255

12.8x34.5+12.8x12.3+46.8x87.2

Answer 1

7.48+3.17-（2.48-6.83）
=7.48-2.48+（3.17+6.83）
=5+10
=15

7.6x7/4+17.5x6/25
=7.6x1.75+1.75x2.4
=(7.6+2.4)x1.75
=10x1.75
=17.5

1333305/2x88+880x133339/4
=1333305x44+220x133339
=1333305x44+44x666695
=44x(1333305+666695)
=44x8000000
=352000000

3.6x11.1+1.2x66.7
=1.1x33.3+1.1x66.7
=1.1x(33.3+66.7)
=1.1x100
=110

7.2x14.5+17x2.8
=7.2x14+1.7x14+7.2x0.5
=(7.2+1.7)x14+3.6
=9.9x14+3.6
=10x14-9.9+3.6
=140-6.3
=133.7

256x254/255+254x1/255
=(256+1)x254/255
=257x(1-1/255)
=257-257/255
=255又253/255

12.8x34.5+12.8x12.3+46.8x87.2
=12.8x(34.5+12.3)+46.8x87.2
=12.8x46.8+46.8x87.2
=(12.8+87.2)x46.8
=100x46.8
=4680