In this question whats my mistake pls once tell

Remember in this type of cases do one thing ,dim U =no. of variables - no . of restrictions.... nd det = 5 is here soo rank of A is 3

here U is a space which have all those elements (a,b,c)€ R3 which satisfied the given three conditions. here when we solve all three equations then we get a=0 ,b=0 ,c=0 means U ha...