Question

(12. Efectuează, utilizând factorul comun: a) 110 + 220 + 330 + 440 + 550; c) 5 + 10 +15+20 + 25 + 30 + 35; e) 123 · 389 + 123 · 11 - 100 · 123; g) 739 · 2016 - 2016 +262 · 2016; .​

Answer 1

Răspuns:

$a)110 + 220 + 330 + 440 + 550 = 110(1 + 2 + 3 + 4 + 5) = 110 \times 15 = 1650$

$c)5 + 10 + 15 + 20 + 25 + 30 + 35 = 5(1 + 2 + 3 + 4 + 5 + 6 + 7) = 5 \times 28 = 140$

$e)123 \times 389 + 123 \times 11 - 100 \times 123 = 123(389 + 11 - 100) = 123 \times 300 = 36900$

$g)739 \times 2016 - 2016 + 262 \times 2016 = 2016(739 - 1 + 262) = 2016 \times 1000 = 2016000$