问几道有理数计算题,①(-5)+(-3)-(-2)+(+7)-(-9)②-1/3-1/2+1/4-1/6

问题描述:

问几道有理数计算题,
①(-5)+(-3)-(-2)+(+7)-(-9)
②-1/3-1/2+1/4-1/6

①=-5-3+2+7+9=10
②=-4/12-6/12+3/12-2/12=-9/12=-3/4

①(-5)+(-3)-(-2)+(+7)-(-9)=-5-3+2+7+9=10这一条只要记住括号前面是+号的,把括号去掉就不用变号;括号前面是减号的,去括号就要变号(加号变减号,减号就变加号)②-1/3-1/2+1/4-1/6 =-4/12-6/12+3/12-2/12...