## Algebra: A Combined Approach (4th Edition)

$2\sqrt {11}$ units $\approx6.633$ units
Let $P=(x_{1},y_{1})=(-\sqrt 5,-\sqrt {11})$ and $Q=(x_{2},y_{2})=(-\sqrt 5,-3\sqrt {11})$ Finding the distance between P and Q, $d(P,Q)=\sqrt {(x_{2}-x_{1})^{2}+(y_{2}-y_{1})^{2})}$ $d(P,Q)=\sqrt {(-\sqrt 5-(-\sqrt 5))^{2}+(-3\sqrt {11}-(-\sqrt {11}))^{2}}$ $d(P,Q)=\sqrt {(-\sqrt 5+\sqrt 5))^{2}+(-3\sqrt {11}+\sqrt {11}))^{2}}$ $d(P,Q)=\sqrt {(0))^{2}+(-2\sqrt {11}))^{2}}$ $d(P,Q)=\sqrt {0+4(11)}$ $d(P,Q)=\sqrt {44}$ $d(P,Q)=\sqrt {4\times11}$ $d(P,Q)=2\sqrt {11}\approx6.633$