1

$\begin{array}{cc}y& =2x+4\\ y& =-3+2x\end{array}$

parallel

skew

perpendicular

✗✓

2

$\begin{array}{cc}y& =7x-8\\ y& =-2-\frac{1}{7}x\end{array}$

parallel

skew

perpendicular

✗✓

3

$\begin{array}{cc}y& =\frac{1}{3}x-3\\ y& =3x+3\end{array}$

parallel

skew

perpendicular

✗✓

4

$\begin{array}{cc}y& =4x-8\\ y& =8x-8\end{array}$

parallel

skew

perpendicular

✗✓

5

$\begin{array}{cc}y& =4x+17\\ y& =1-\frac{1}{4}x\end{array}$

parallel

skew

perpendicular

✗✓

6

$\begin{array}{cc}y& =5+3x\\ y& =3x-7\end{array}$

parallel

skew

perpendicular

✗✓