1. The line of intersection of the two planes is parametrized as x = 1 + 6t, y = t, z = 1 + 7t, where t is a scalar parameter. 2. The projection of 2u - 3v onto u + 2v is found by taking the dot product of 2u - 3v with the unit vector in the direction of u + 2v. 3. The document provides an example of finding the line of intersection between two planes and discusses that parametric equations are valid so long as they use a direction vector of the line and a point on the line.