please do all of them steps by steps with details explanation. thank you

3.- Convert: [10 points] a) from (26)10 to (?)2 b) from (2343)8 to (?)16 c) from (0.6800)10 to (?)2 d) from (0.111)2 to (?)10 4.- [10 points] Using binary numbers of 8 bits each, convert to binary and solve the following arithmetic operations using two's complement representation: a) (13)10(25)10 b) (13)10(18)10