Question Number 63836 by gunawan last updated on 10/Jul/19 | ||
$$\mathrm{If}\:{n}\:\in\:{N},\:\mathrm{then}\:\mathrm{the}\:\mathrm{sum}\:\mathrm{of}\:\mathrm{the}\:\mathrm{coefficients} \\ $$$$\mathrm{in}\:\mathrm{the}\:\mathrm{expansion}\:\mathrm{of}\:\:\mathrm{the}\:\mathrm{binomial} \\ $$$$\left(\mathrm{5}{x}−\mathrm{4}{y}\right)^{{n}} \:\mathrm{is} \\ $$ | ||
Commented by kaivan.ahmadi last updated on 10/Jul/19 | ||
$${x}={y}=\mathrm{1}\Rightarrow\left(\mathrm{5}−\mathrm{4}\right)^{{n}} =\mathrm{1} \\ $$ | ||