图过程
(－2.1)×6.5×(－3/7) =(－2.1)×(－3/7) ×6.5=0.9×6.5=5.85
g
(－2.1)×6.5×(－3/7)=(－2.1)×(－3/7) ×6.5=0.9×6.5=5.85
