Question

Example 14. Find the intersection between two planes x−3y−2z = 2 and 2x+y+3z = 1

Solution:

(1)n1 ×n2 =<−7,7,7>=7<−1,1,1>.
(2) To find one intersection point, we let z = 0. Then x = 5/7,y = −3/7

where did they get
z = 0
x = 5/7
y = 3/7

For the point on the line?