Respostas

2014-01-20T16:17:14-02:00
7a+5b-9c+13b+10c-5a-8b+c
(7-5)a+(5+13-8)b+(-9+10+1)c
=2a+10b+2c
  • Usuário do Brainly
2014-01-20T17:39:33-02:00
Soma os termos iguais.
7a+5b-9c+13b+10c-5a-8b+c
7a-5a+5b+13b-8b-9c+10c+c
2a+10b+2c
Pronto!