Intermediate Algebra for College Students (7th Edition)

$\sqrt{90}$
The distance formula from $P_1(x_1,y_1)$ to $P_2(x_2,y_2)$ is $d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$. Hence here: $d=\sqrt{(6-(-3))^2+(-1-(-4))^2}=\sqrt{(9)^2+(3)^2}=\sqrt{90}$