Question

Care este rezultatul acestiu calcul
(1+2+...+20):14

Answer 1

(1+2+3+...+20)÷14= $\frac{(1+20)*20}{2}$÷14 =21·10÷14= 210 ÷ 14 = 15

Answer 2

$(1+2+...+20):24=20(20+1):2:14=(20*21):2:14= \\ =420:2:14=210:14=15$