Question

now please solve this

Answer 1

i hope its clear..if not let me know

Answer 2

$a(b + c) = \binom{2 \: 1}{0 \: 0} \binom{3 \: 7}{4 \: 3} = \binom{6 + 4 \: 14+ 3}{0 + 0 \: 0 + 0} = \binom{10 \: 17}{0 \: 0} \\ ab = \binom{2 \: 1}{0 \: 0} \binom{2 \: 3}{4 \: 1} = \binom{8 \: 7}{0 \: 0} \\ ac = \binom{2 \: 1}{0 \: 0} \binom{1 \: 4}{0 \: 2} = \binom{2 \: 10}{0 \: 0} \\ ab + ac = \binom{10 \: 17}{0 \: 0} \\ lhs = rhs \\ hence \: proved \:$