Question

let a,b,c is the element of R, if a<b, using properties if real number .prove that a-c<b-c​

Answer 1

$\text{a, b , c} \in \mathbb{R } \ , \ \text{and } \text a<\text b$

let's  subtrac c from both sides os a < b :

$\text a < \text b$

$\text a - \text c < \text b -\text c$

remains valid, so it's proven.