Question

8分之7乘以九分之五加上87.5乘以九分之十三怎么计算？

Answer 1

7/8 x5/9 +87.5 x13/9
【7/8化成小数】
=0.875 x5/9 +87.5 x13/9
【提取0.875】
=0.875x(5/9 +100x13/9)
=0.875x1305/9
【用9约分】
=0.875x145
=0.875x5x29

=4.375x(30-1)
=131.25-4.375
=126.875

Answer 2

7/8×5/9+87.5×13/9
=7/8×5/9+175/2×13/9
可以提取出(5×7)/(2×9)
=35/18(1/4+5×13)
=35/18×261/4
=1015/8≈126.875

Answer 3

7／8×5／9＋87.5×13／9
＝7／8×5／9＋（90－2.5）×13／9
＝7／8×5／9＋90×13／9一2.5×13／9
＝1／9×（35／8－65／2）＋130
＝5／9×（7／8－52／8）＋130
＝5／9×（－45／8）＋130
＝－25／8＋130
＝126＋7／8
＝126又7／8

Answer 4

7/8×5/9+87.5×23/9
=0.875×5/9+87.5×13/9
=0.875×5/9+0.875×100×13/9
=0.875×(5/9+1300/9)
=0.875×145
=126.875