3-9 할리데이 10판 솔루션 일반물리학

$$\begin{cases} \vec a = (5.0)\hat i - (4.0)\hat j + (2 . 0)\hat k\\ \vec b = (-2.0m)\hat i +(2 .0m)\hat j + (5.0m)\hat k\\ \end{cases}$$
(a)$\vec a + \vec b$ $$\vec a + \vec b = \(5.0-2.0m \)\hat i + \(-4.0+2.0m \)\hat j + \(2.0+5.0m \)\hat k$$
(b)$\vec a- \vec b$ $$\vec a - \vec b = \(5.0+2.0m \)\hat i + \(-4.0-2.0m \)\hat j + \(2.0-5.0m \)\hat k$$
(c)$\vec a - \vec b + \vec c = 0, \vec c=?$ $$\begin{aligned} \vec c&=\vec b-\vec a\\ &=\(-5.00-2.00m \)\hat i + \(4.00-2.00m \)\hat j + \(-2.00+5.00m \)\hat k \end{aligned}$$