i want just that three qoustion plz

9. Oue of the following sets is a subspace of P4 (a) {f(x)P4:f(0)=1} (b) {f(x)P4:f(1)=1} (c) {f(x)P4:f(1)=0} (d) {f(x)P4:f(0)=0,f(0)=6} 0. If A is a 43 matrix such that N(A)={0}, and b=0321, th (a) It is possible that Ax=b has infinitely many solutions (b) The system Ax=b has exactly one solution. (c) The system Ax=b has at most one solution. (d) The system Ax=b has no solution 4. Consider the ordered basis E={1,1c2} for R2. If [v]E=(1,1)T, then v= (a) c2 (b) 2e1+e2 (c) e1+e2 (d) (0,1)T