Question

(5+10+15+....+40):(1+2+3+.....+8)va rog dau coroana ajutatima

Answer 1

(5+10+15+....+40):(1+2+3+....+8)=?

5*(1+2+3+.....8)=?

5*(1+8)*8:2=5*9*4=45*4=180(PRIMA PARANTEZA)

1+2+3+...+8=?

(1+8)*8:2=9*4=36(A DOUA PARANTEZA)

180:36=5(REZULTATUL FINAL)

Answer 2

( 5 + 10 + 15 + ...... + 40 ) : ( 1 + 2 + 3 + ....... + 8 ) = 5

= 5 x ( 1 + 2 + 3 + ...... + 8 ) : ( 1 + 2 + 3 + ......+ 8 ) =

= 5

___________________________

sau efectuand calculele :

= 5 x ( 8 x 9 / 2 ) : ( 8 x 9 / 2 ) =

= 5 x 36 : 36 =

= 180 : 36 =

= 5