已知-1<=a+b<=1且-1<=a-2b
问题描述:
已知-1<=a+b<=1且-1<=a-2b
答
-1<=a+b<=1
两边都乘以5
-5
已知-1<=a+b<=1且-1<=a-2b
-1<=a+b<=1
两边都乘以5
-5