I was wondering how to prove this. It always appears to be true when I plug in values.
$a,b,c \in \mathbb{R}\\a\lt b\lt c$
Prove $\forall a,b,c : \left|a + b\right| \space\lt \left|a + c\right|$
I was wondering how to prove this. It always appears to be true when I plug in values.
$a,b,c \in \mathbb{R}\\a\lt b\lt c$
Prove $\forall a,b,c : \left|a + b\right| \space\lt \left|a + c\right|$
This is false. $a = -100, b=-1$ and $c=1$.