please kindly help me solve part 4 and 5 all questions

4. It is claimed that {(1,0,0),(0,1,0),(0,0,0)} is a set of vectors spanning R3. Explain why it is not possible for these vectors to span R3. [C3] 5. Determine whether each of the following statement is true or false. Provide a brief explanation for each answer. [C6] a) a+ba b) a+b=a+c implies b=c