矿井下,a.b.c三处高度分别为-47.5m,-128.6米,-84.6米.求a处比b处高多少米?a处比c处高多少米?

题目

矿井下,a.b.c三处高度分别为-47.5m,-128.6米,-84.6米.求a处比b处高多少米?a处比c处高多少米?
不理解,矿井下,是负的越多高,还是负的越少高呢?

答案

-47.5-(-128.6)=-47.5+128.6=81.1m
-47.5-(-84.6)=-47.5+84.6=37.1m