Step 1: The slope of line \( PQ \) is given by: \[ m_{PQ} = \frac{y_2 - y_1}{x_2 - x_1} = \frac{1 - 4}{3 - (-3)} = \frac{-3}{6} = -\frac{1}{2} \] Step 2: The slope of the line perpendicular to \( PQ \) is the negative reciprocal of \( m_{PQ} \).
Hence: \[ m_{{perpendicular}} = -\frac{1}{-\frac{1}{2}} = 2 \]
If $ X = A \times B $, $ A = \begin{bmatrix} 1 & 2 \\-1 & 1 \end{bmatrix} $, $ B = \begin{bmatrix} 3 & 6 \\5 & 7 \end{bmatrix} $, find $ x_1 + x_2 $.