简便计算怎么做？

▲87x3/36=87x1/12=87/12=29/4=7又1/4

▲4/7 x 11/31 + 11/31÷7/14

=4/7 x 11/31 + 11/31x2

=11/31 x(4/7 + 2)

=11/31 x 18/7

=198/217

▲ 2/7x 5/9 x48 x14=(2/7 x 14)x5/9 x 48=20 x16/3=320/3=106又2/3

▲15÷3/5 - 3/5÷15=15 x 5/3 -3/5 x 1/15=25 - 1/25=24又24/25

▲2014 x 2013/2015

=[(2015-1)x(2015-2]/2015

=(2015²-2015-2x2015+2)/2015

=2015-1-2+2/2015

=2012又2/2015

▲36x(1/3 - 1/6- 1/9)=12-6-4=2

▲15÷4/3 + 0.85x75=15x3/4 +85x3/4=3/4 x(15+85)=75

▲(7/8 +3/16)÷13/16=(7/8+3/16)x16/13=14/13 + 1=2又1/13

▲67x67/68 =(68-1)(68-1)/68 =(68²-68-68+1)/68 =68-1-1 + 1/68=66又1/68

▲17/24 x 3/4 +17/24 ÷4

= 17/24 x 3/4 +17/24 x 1/4

=1/4 x(51/24 +17/24)

= (17/6)/4

=17/24

▲55x3/7 +3÷1=165/7+3=23又4/7+3=26又4/7

▲3.7x5+6.25÷ 1/7

=3.7x5+6.25x7

=5x(3.7+1.25x7)

=5x(3.7+8.75)

=5x12.45

=62.25

这么多？？？？？？？？？？？？！！！！！！！！！！！！！！！！！！！！！

1、87×3／36
＝（84＋3）×1／12
＝84×1／12＋3×1／12
＝7又1／4