Given that, r = i + 2j and n = -i + 3j, to find |2n - r|
2n = 2(- i + 3j) = - 2i + 6j
2n - r = [- 2i + 6j] - [ i + 2j] = -3i + 4j
|2n - r| = |-3i + 4j| = √(−3)2+42 = √9+16 = √25 = 5.0