Solution to Exercise 3.12.
Common sense is the collection of prejudices acquired by age eighteen.
—Albert Einstein (1879–1955)

Exercise 3.12. Find the point of intersection of the lines [–2, 4, –3] and [3, –5, 2].

By Proposition 3.2,  Evaluate the determinant to obtain –7l₁ – 5l₂ – 2l₃ =0.  Since we need the third coordinate of a point to be 1, we divide by –2 to obtain   Rewrite as a matrix equation  Thus, the point of intersection is