[tex]\\|\vec AB|=\sqrt{(-1-4)^2+(-19+7)^2}=\sqrt{25+144}=\sqrt{169}=13[/tex]
A=(4,-7) B=(-1,-19)
Xa Ya Xb Yb
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|AB| = √[(Xb - Xa)² + (Yb - Ya)²)] =√[(-1 - 4)² + (-19 + 7)²)] =
√[(-5)² + (-12)²)] = √(25 + 144) = √169 = 13 [j]
