29.94-(19.94+12.8)+2.8用简便计算尽快

问题描述:

29.94-(19.94+12.8)+2.8用简便计算
尽快

(29.94-19.94)+(-12.8+2.8)= 0

(29.94-19.94)-(12.8+0.2)+(2.8+0.2)
10-13+3
0

=(29.94-19.94)-(12.8-2.8)=10-10=0

29.94-(19.94+12.8)+2.8
=29.94-19.94-12.8+2.8
=(29.94-19.94)-(12.8-2.8)
=10-10
=0

29.94-(19.94+12.8)+2.8
=29.94-19.94-12.8+2.8
=(29.94-19.94)-(12.8-2.8)
=0