Answer:
[tex]\bold{d=4\sqrt5\approx8.94}[/tex]
Step-by-step explanation:
[tex]d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}\\\\(-1,4)\quad\implies\quad x_1=-1\,,\ \ y_1=4\\\\(-5,-4)\quad\implies\quad x_2=-5\,,\ \ y_2=-4\\\\d=\sqrt{(-1+5)^2+(4+4)^2}= \sqrt{4^2+8^2}=\sqrt{80}=\sqrt{16\cdot5}=4\sqrt5\approx8.94[/tex]
