as i seeing the graph
the slope of the line perpendicular to the given line will be
m1 = 1
because the slope of the given line is, m2= -1
for perpendicular lines,
[tex]\begin{gathered} m_1\times m_2=-1 \\ m_1\times-1=-1 \\ m_1=1 \end{gathered}[/tex]
so the slope of the perpendicular line is 1
