Răspuns:
Explicație pas cu pas:
4309 : 11 = 391 rest 8
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23*21 + 20 = 483 + 20 = 503
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37*49 + 18*49 + 55*51 = 49*(37 + 18) + 55*51 = 49*55 + 55*51
= 55*(49 + 51) = 55*100 = 5500
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55/66 - 44/55 = 5/6 - 4/5 = 25/30 - 24/30 = 1/30
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(7/9 + 77/99 + 777/999)*1/3 = (7/9 + 7/9 + 7/9)*1/3 = 21/9*1/3 = 7/9
