Răspuns :
(11+1)×(13+1)×(15+1)......×(37+1)=(11×13×15×......×37)+(1+1+1+......+1) de ori
11×(37+1)×37:2=
11×37×38:2=
407×19=spui raspunsul
11×(37+1)×37:2=
11×37×38:2=
407×19=spui raspunsul