大家帮我看看这几道数学计算题对么!
计算
(+15)-(-21)+(-8)-17
=(+15)+21+(-8)+(-17)
=36+(-8)+(-17)
=11
(2)
-3/2+(-6/1)-(-4/1)-2/1
=3/2+(-6/1)+4/1+(-2/1)
=-12/8+(-12/2)+12/3+(-12/6)
=-12/10+12/3+(-12/6)
=-12/3
(3)
(2又5/2)-(-4.7)-(+0.5)+(+2.4)+(3又5/1)
=(2又5/2)+4.7+(-0.5)+2.4+(3又5/1)
=(-2.4)+4.7+(-0.5)+2.4+(-3.2)这里我把两个带分数化成小数了
=2.3+(-0.5)+2.4+(-3.2)=1
大家说我做得对么 !