(-5)*(+7 1/3)+7*(-7 1/3)-(+12)*(-7 1/3)=多少?(要用简便方法)

问题描述:

(-5)*(+7 1/3)+7*(-7 1/3)-(+12)*(-7 1/3)=多少?(要用简便方法)

(-5)*(+7 1/3)+7*(-7 1/3)-(+12)*(-7 1/3)
= (- 5 - 7 + 12)*(+7 1/3)
= 0 *(+7 1/3)
= 0