$\vec b$

$\vec a$

$\vec a-\vec b$

A = (0, 4)
C = (2, 7)
B = (4, 3)
b = Vector(A, B)
a = Vector(A, C)
w = Vector(B, C)
Text1: "\textcolor{blue}{\vec{a}}-\textcolor{blue}{\vec{b}}=\textcolor{blue}{" + (LaTeX[a]) + "}-\textcolor{blue}{" + (LaTeX[b]) + "}=\textcolor{red}{" + (LaTeX[w]) + "}"