Find the sum of vectos `a = hat(i)- 2hat(j)+hat(k),b=-2hat(i)+4hat(j)+5hat(k)` and `c=hat(i)-6hat(j)-7hat(k)`.

Explanation

Here , given `a=hat(i)-2hat(j)+hat(k),b=-2hat(i)+4hat(j)+5hat(k),c=hat(i)-6hat(j)-7hat(k)` Sum of these vectors can be calculated by adding their `hat(i),hat(j) and hat(k)` components.
`therefore vec(a)+vec(b)+vec(c ) = (hat(i) -2hat(j)+hat(k))+(-2hat(i)+4hat(j)+5hat(k))+(hat(i)-6hat(j)-7hat(k))`
`= (hat(i)-2hat(i)+hat(i))+(-2hat(j)+4hat(j)-6hat(j))+(hat(k)+5hat(k)-7hat(k))`.
`=0hat(i) -4hat(j)-hat(k)=-4hat(j)-hat(k)`.