Question

Repede ,va rog!
Dau coroana!

Answer 1

a)2+3+4+...+50=

(2+50)×49/2=

52×49/2=

26×49=

1274

b)1+2+3+....+500=

(500×501):2=

250×501=

125250

c)1+97+2+999+3+198=

1099+201=

1300

d)1+2+3+...124=

(124×125):2=

62×125=

7750

e)2+4+6+...+600=

2(1+2+3+....300)=

2×(300×301):2=

2×150×301=

300×301=

90300

f)15+16+17+....+70=

(15+70)×56/2=

85×28=

2380