Question

2/7乘以（-5/12）-5/7乘以5/12+（-5/3）乘以（-1/4）做，详细点

Answer 1

转化：=（-10）/(7*12)-25/(7*12)+5/12
=（-35）/(7*12)+(5*7)/(7*12)
=（-35）/(7*12)+35/(7*12)
=0
注释：乘号用*表示

Answer 2

2/7×﹙-5/12﹚－5/7×5/12＋﹙-5/3﹚×﹙-1/4﹚
=-2/7×5/12－5/7×5/12＋5/12
=-1×5/12＋5/12
=－5/12＋5/12
=0