(1 point) Let H be the subset of R3 of all points on the plane 7x + 4y + 2z = 0. Is H a subspace of R3? 1. Does H contain the zero vector of R3? choose 2. Is H closed under addition? If it is, enter CLOSED. If it is not, enter two vectors in H whose sum is not in H, using a comma separated list and syntax such as , 4. Is H a subspace of R? You should be able to justify your answer by writing a complete, coherent, and detailed proof based on your answers to parts 1-3. choose (1 point) Let H be the subset of R2 of all points on the line 4x 3y = 12. Is H a subspace of R? 1. Does H contain the zero vector of R2? choose 2. Is H closed under addition? If it is, enter CLOSED. If it is not, enter two vectors in H whose sum is not in H, using a comma separated list and syntax such as , 3. Is H closed under scalar multiplication? If it is, enter CLOSED. If it is not, enter a scalar in Rand a vector in H whose product is not in H, using a comma separated list and syntax such as 2, , 4. Is H a subspace of R? You should be able to justify your answer by writing a complete, coherent, and detailed proof based on your answers to parts 1-3. choose (1 point) Let H be the subset of R2 of all points on the line 4x 3y = 12. Is H a subspace of R? 1. Does H contain the zero vector of R2? choose 2. Is H closed under addition? If it is, enter CLOSED. If it is not, enter two vectors in H whose sum is not in H, using a comma separated list and syntax such as , 3. Is H closed under scalar multiplication? If it is, enter CLOSED. If it is not, enter a scalar in Rand a vector in H whose product is not in H, using a comma separated list and syntax such as 2,