Question

Find the distance BF for the points B(1,-1) and F(-3,5)

Answer 1

Use the distance formula: 
$\sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$

Plug in the given coordinates: 
$\sqrt{(-3-1)^2 + (5-(-1))^2}$

Simplify: 
$\sqrt{(-3-1)^2 + (5+1))^2}$

$\sqrt{-4^2+ 6^2}$

$\sqrt{16+36}$

$\sqrt{52}$
You can leave it as: $\sqrt{52}$or in decimal form as: 7.2