Exercice sous espace vectoriel de R^3 • Les parties suivantes sont-elles des sev de R^3? sup prépa

http://www.jaicompris.com/lycee/math/... Be able to demonstrate that a set is or is not a vector subspace of R^3. Are the following subspaces vector subspaces of R^3? E={(x,y,z)∈R^3 | x-y+z=0} E={(x,y,z)∈R^3 | x-y+z=1} E={(x,y,z)∈R^3 | x²-y²=0} Mathematics courses: preparatory math, advanced math, MPSI, PCSI, MP2I, PTSI, ECS - university - higher education, linear algebra