Please answer questions 3, 4 and 5 fully. Will rate. Thanks

Either prove or disprove the ambiguity of the following grammar. rightarrow rightarrow - | rightarrow X | Y | Z Rewrite the following grammar to give + precedence over * and force + to be right associative: rightarrow = rightarrow A | B | C rightarrow + | rightarrow * | rightarrow () | Convert the following EBNF to BNF: rightarrow {[| S] } rightarrow | rightarrow | rightarrow A bar | B | C | D | E | F | G rightarrow a | b | c | d | e | f | g rightarrow 0 bar | 1 | 2 | 3 |4 |5 | 6 | 7 | 8 | 9