a) A(-3, -1) e B(9, 4)
dAB = [tex]\sqrt{(xb - xa)^{2} + (yb - ya)^{2} }[/tex]
dAB = [tex]\sqrt{(9 - (-3))^{2} + (4 - (-1))^{2} }[/tex]
dAB = [tex]\sqrt{(9 + 3)^{2} + (4 +1)^{2} }[/tex]
dAB = [tex]\sqrt{(12)^{2} + (5)^{2} }[/tex]
dAB = [tex]\sqrt{144 + 25 }[/tex]
dAB = [tex]\sqrt{169}[/tex]
dAB = 13
