The value of the expression \({ _{ }^{ k-1 }{ C } }_{ k-1 }+{ _{ }^{ k }{ C } }_{ k-1 }+....{ _{

The value of the expression \({ _{ }^{ k-1 }{ C } }_{ k-1 }+{ _{ }^{ k }{ C } }_{ k-1 }+....{ _{ - চর্চা