1. **Problem:** Decide if the graphs of the pair of lines are parallel, perpendicular, or neither for (a) $y = -2x + 1$ and $y = 9 - 2x$. 2. **Recall:** - Lines are **parallel** if their slopes are equal. - Lines are **perpendicular** if the product of their slopes is $-1$. 3. **Find slopes:** - First line: $y = -2x + 1$ has slope $m_1 = -2$. - Second line: $y = 9 - 2x$ can be rewritten as $y = -2x + 9$, so slope $m_2 = -2$. 4. **Compare slopes:** - Since $m_1 = m_2 = -2$, the lines are parallel. **Final answer:** The lines are parallel.