(a) Represent the equations of lines $l_1$ and $l_2$ in vector form and check whether they are intersecting or not. $l_1 : \frac{x+3}{-3} = \frac{y-1}{1} = \frac{z-5}{5}$ $l_2 : \frac{x+1}{-1} = \frac{2-y}{-2} = \frac{z-5}{5}$ OR