Two lines are parallel if their slopes are equal.
In this case we have the lines:
![\begin{gathered} y-7x=6 \\ y+7x=8 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/wvp5084j9e468bwsd1e94x63e58seeyi7z.png)
If we rearrange them in slope-intercept form, we get:
![\begin{gathered} a)y-7x=6\longrightarrow y=7x+6 \\ b)y+7x=8\longrightarrow y=-7x+8 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/896398rc3nin7fega65zecsnon7m3gkk49.png)
As line a has a slope m=7 and line has a slope m=-7, the lines have different slopes so they are not parallel.
![\begin{gathered} m_a=7 \\ m_b=-7 \\ 7\\eq-7\longrightarrow\text{not parallel} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/fhih4106ur6uuy00bmroksz9v9sjch812n.png)
Answer: The lines are not parallel