Question

CALCULEAZA, GRUPAND CONVENABIL TERMENII:

896+897+898+...+904=
1000+999+998+...+991=


VA ROG SA M,A AJUTATI

Answer 1

896+904=1800 897+903=1800 898+902=1800 899+901=1800 1800*4+900=8200 1000+991=1991 999+992=1991 998+993=1991 997+994=1991 996+995=1991 1991*5=9995

Answer 2

896 + 897 + 898 + 899 + 900 + 901 + 902 + 903 + 904 =
(896 + 904) + (897 + 903) + (898 + 902) + (899 + 901) + 900 = 
1800 + 1800 + 1800 + 1800 + 900 = 
8100

1000 + 999 + 998 + 997 + 996 + 995 + 994 + 993 + 992 + 991 =
1000 + (999 + 991) + (998 + 992) + (997 + 993) + ( 996 + 994) + 995 = 
1000 + 995 + 4 * 1990 =
1995 + 7960 = 
9955