1. The problem statement, all variables and given/known data Give the Cartesian equation of the following hyperplane: The plane spanned by (1,1,1) and (2,1,0) and passing through (1,1,2) 2. Relevant equations 3. The attempt at a solution I keep getting 4 = -2x(sub1) + -2x(sub2) +x(sub3). However, the answer is x(sub1) - 2x(sub2) + x(sub3) = 1. Someone please help! What I am doing wrong? Gabba guy come back you seemed nice. You say (a,b,c) + t(d,e,f) is not a plane but a line. But using the other equation doesn't work either.