3.5×(-5/7)-(-5/7)×2.5-5/7×(-1/2) 求计算过程
问题描述:
3.5×(-5/7)-(-5/7)×2.5-5/7×(-1/2) 求计算过程
如题,急!
答
解3.5×(-5/7)-(-5/7)×2.5-5/7×(-1/2)
=-3.5×(5/7)+(5/7)×2.5+5/7×(1/2)
=5/7(-3.5+2.5+0.5)
=5/7×(-0.5)
=-5/7×1/2
=-5/14.