A.  $\frac{x-2}{1}=\frac{y-1}{-4}=\frac{z}{-2}$

B.  $\frac{x-2}{-1}=\frac{y-1}{-4}=\frac{z}{2}$  

C.  $\frac{x-2}{-1}=\frac{y-1}{-3}=\frac{z}{2}$

D.  $\frac{x-2}{-3}=\frac{-y-1}{-4}=\frac{z}{-2}$ 

A. z - 2z - 1 = 0

B. x + y - z - 1 = 0

C. 2x - y + 3z - 2 = 0

D. 2x + y + 3z - 2 = 0

A. 2x + y - 2z + 4 = 0

B. 2x + y + 2z - 4 = 0

C. 2x + y - 2z - 4 = 0

D. 2x + y + 2z + 4 = 0

$A. d:\left\{\begin{array}{c}x=2+t\\ y=1-4t\\ z=-2t\end{array}\right.$

$\mathbf{B}. d:\left\{\begin{array}{c}x=2-t\\ y=1+t\\ z=t\end{array}\right.$

$\mathbf{C}\mathbf{.} d:\left\{\begin{array}{c}x=1+t\\ y=-1-4t\\ z=2t\end{array}\right.$

$\mathbf{D}. d:\left\{\begin{array}{c}x=2+2t\\ y=1+t\\ z=-t\end{array}\right.$

A.  $\frac{x-7}{1}=\frac{y-2}{-1}=\frac{z-4}{1}$

B. $\frac{x-1}{7}=\frac{y+1}{2}=\frac{z-1}{4}$

C. $\frac{x+1}{7}=\frac{y-1}{-2}=\frac{z+1}{4}$

D. $\frac{x+1}{7}=\frac{y-1}{2}=\frac{z+1}{4}$