Answer:
a).
S.I units of length is meters. So we've to change cm → m
[tex]{ \rm{1 \: cm \: \dashrightarrow \: 0.01 \: m}} \\ { \rm{0.009 \: cm \: \dashrightarrow \: (0.009 \times 0.01)}} \\ \\ = { \underline{ \rm{ \: \: 0.00009 \: m \: \: }}}[/tex]
b).
km → m
[tex]{ \rm{1 \: km \: \dashrightarrow \: 1000 \: m}} \\ { \rm{25 \: km \: \dashrightarrow \: (25 \times 1000)}} \\ \\ = { \underline{ \rm{ \: \: 25000 \: m \: \: }}}[/tex]
