计算(﹣5)-(+3)+(-9)﹣(﹣7)+1/2的值为(
问题描述:
计算(﹣5)-(+3)+(-9)﹣(﹣7)+1/2的值为(
答
=7+1/2-(5+3+9) =7.5-17 =-9.5
答
(﹣5)-(+3)+(-9)﹣(﹣7)+1/2=-19/2