Respostas

2014-09-03T10:57:58-03:00
1 ) ( 5x ) + ( - 5x ) = 5x - 5x = 1


2 ) ( + 15x ) - ( - 3x ) - ( + 7x ) + ( - 2x ) =

15x + 3x - 7x - 2x = 9x


3 ) ( 3n ) + ( - 8n ) + ( + 4n ) - ( - 5n ) - ( - n )

3n - 8n + 4n + 5n + n = 5n