Răspuns :
21x(56+33)=21x89=1869
21x56+21x33=1176+693=1869
(451-239)x71=212x71=15.052
451x71 - 239x71=32.021-16969=15.052
21x56+21x33=1176+693=1869
(451-239)x71=212x71=15.052
451x71 - 239x71=32.021-16969=15.052