Respuesta :

Answer:

The length of the AR is  [tex]3\sqrt{17}[/tex]  or [tex]12.4[/tex] units.

Step-by-step explanation:

Given the endpoints of a line segment AR

  • A(8, -2)
  • R(-4, 1)

We can calculate the length of AR using the formula

[tex]L_{AB}=\sqrt{\left(x_2-x_1\right)^2+\left(y_2-y_1\right)^2}[/tex]

In our case,

  • (x₁, y₁) = (8, -2)  
  • (x₂, y₂) = (-4, 1)

Substituting (x₁, y₁) = (8, -2) and (x₂, y₂) = (-4, 1) in the formula

[tex]L_{AB}=\sqrt{\left(x_2-x_1\right)^2+\left(y_2-y_1\right)^2}[/tex]

        [tex]=\sqrt{\left(-4-8\right)^2+\left(1-\left(-2\right)\right)^2}[/tex]

        [tex]=\sqrt{\left(-4-8\right)^2+\left(1+2\right)^2}[/tex]            ∵ Apply rule:  [tex]-\left(-a\right)=a[/tex]

        [tex]=\sqrt{12^2+3^2}[/tex]

        [tex]=\sqrt{144+9}[/tex]

        [tex]=\sqrt{153}[/tex]

        [tex]=\sqrt{9\times 17}[/tex]

         [tex]=\sqrt{17}\sqrt{3^2}[/tex]          Apply radical rule:   [tex]\sqrt[n]{ab}=\sqrt[n]{a}\sqrt[n]{b}[/tex]

         [tex]=3\sqrt{17}[/tex]              Apply radical rule:   [tex]\sqrt[n]{a^n}=a[/tex]

         [tex]=12.4[/tex]

Therefore, the length of the AR is  [tex]3\sqrt{17}[/tex]  or [tex]12.4[/tex] units.