[tex]\displaystyle\bf\\tg\alpha =\frac{1}{4} \ \ \ ; \ \ \ tg\beta =\frac{5}{3}\\\\\\tg(\alpha - \beta )=\frac{tg\alpha -tg\beta }{1+tg\alpha \cdot tg\beta }=\frac{\dfrac{1}{4}-\dfrac{5}{3} }{1+\dfrac{1}{4} \cdot\dfrac{5}{3} } =\frac{-\dfrac{17}{12} }{1+\dfrac{5}{12} } =\\\\\\=-\frac{\dfrac{17}{12} }{\dfrac{17}{12} }=-1\\\\\\\boxed{\alpha - \beta =135^\circ}[/tex]