The distance between points $ A $ and $ B $ is :
$$ d(A, B) = \frac{\sqrt{ 36637 }}{ 10 } $$To find distance between points $ A(x_1,y_1)$ and $ B(x_2,y_2)$, we use formula:
$$ \color{blue}{ d(A,B) = \sqrt{(x_2 - x_1)^2+(y_2 - y_1)^2} } $$In this example we have:
$$ \begin{aligned} & A \left(-\dfrac{ 21 }{ 10 },~-\dfrac{ 48 }{ 5 }\right) \implies x_1 = -\frac{ 21 }{ 10 } ~~\text{and}~~ y_1 = -\frac{ 48 }{ 5 } \\[1 em] & B \left(-\dfrac{ 107 }{ 10 },~\dfrac{ 15 }{ 2 }\right) \implies x_2 = -\frac{ 107 }{ 10 } ~~\text{and}~~ y_2 = \frac{ 15 }{ 2 } \end{aligned} $$Substituting $ x_1 $, $ x_2 $, $ y_1 $ and $ y_2 $ into the formula above yields:
$$ \begin{aligned} d(A,B) & = \sqrt{\left( -\frac{ 107 }{ 10 } - \left( -\frac{ 21 }{ 10 }\right) \right)^2 + \left( \frac{ 15 }{ 2 } - \left( -\frac{ 48 }{ 5 }\right) \right)^2} \\[1 em] d(A,B) & = \sqrt{ \left(-\frac{ 43 }{ 5 }\right)^2 + \left(\frac{ 171 }{ 10 }\right)^2 } \\[1 em] d(A,B) & = \sqrt{ \frac{ 1849 }{ 25 } + \frac{ 29241 }{ 100 } } \\[1 em] d(A,B) & = \sqrt{ \frac{ 36637 }{ 100 } } \\[1 em] d(A,B) & = \frac{\sqrt{ 36637 }}{ 10 } \end{aligned} $$