Answer:
3
Step-by-step explanation:
[tex]\bold{METHOD\ 1:}\\\\\text{Use the formula:}\\\\d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}\\\\\text{Substitute the coordinates of the give points:}\\\\d=\sqrt{(1-(-2))^2+(-1-(-1))^2}=\sqrt{(1+2)^2+(-1+1)^2}\\\\=\sqrt{3^2+0^2}=\sqrt9=3[/tex]
[tex]\bold{METHOD\ 2:}\\\\\text{We can see that the second coordinates of the points (ordinate) are the same.}\\\text{Therefore, the distance between these points is equal to the distance}\\\text{ between the first coordinates (abscissa).}\\\\d=|1-(-2)|=|1+2|=|3|=3[/tex]
