Question

Calculați ,folosind faptul ca adunarea numerelor raționale este comutativa si asociativa:
7/17+23/17+15/17=
19/29+13/29+1/29+7/29=
1/103+2/103+3/103+...+9/103=
5/13+4/26+25/13+16/26=

Answer 1

(7+23+15)/17 = 45/17
(19+13+1+7)/29 = 40/29
(1+2+3+...+9)/103 = 45/103
(5×2+4+25×2+16)/26 = 80/26 = 40/13

Answer 2

= (7+23+15)/17
= 45/17
2))))
=(19+13+1+7)/29
= 40/29
3))
=(9•10:2)/103
= (90:2)/103
=45/103
4)))
= 5/3 + 2/13 + 25/13 + 8/13
= (5+2+25+8)/13
= 40/13