The vector \(\displaystyle A = 3i + j - k\) is normal to the plane \(\displaystyle M1 \)and the vector \(\displaystyle B = 2i - j + k\) is normal to a second plane \(\displaystyle M2\)

Do the two planes necessarily intersect if they are both extended indefinetly? If the two planes do intersect, find a vector which is parallel to their line of intersection.

Thanks guys!