Răspuns:
[tex]a)110 + 220 + 330 + 440 + 550 = 110(1 + 2 + 3 + 4 + 5) = 110 \times 15 = 1650[/tex]
[tex]c)5 + 10 + 15 + 20 + 25 + 30 + 35 = 5(1 + 2 + 3 + 4 + 5 + 6 + 7) = 5 \times 28 = 140[/tex]
[tex]e)123 \times 389 + 123 \times 11 - 100 \times 123 = 123(389 + 11 - 100) = 123 \times 300 = 36900[/tex]
[tex]g)739 \times 2016 - 2016 + 262 \times 2016 = 2016(739 - 1 + 262) = 2016 \times 1000 = 2016000[/tex]
