[tex]\text {Distance = } \sqrt{(Y_2-Y1)^2 + (X_2-X_1)^2} [/tex]
[tex]\text {Distance = } \sqrt{(5 - (-4))^2 + (1-1)^2} [/tex]
[tex]\text {Distance = } \sqrt{81 + 0} [/tex]
[tex]\text {Distance = } \sqrt{81} [/tex]
[tex]\text {Distance = } 9 \text { units}[/tex]
