Sečti mnohočleny:
\large \left( 5a + 7b- 9c\right) + \left( 6b + 4c-9a\right) - \left( c + a- b\right)
\large =- 5a + 14b- 6c
\large =- 4a + 14b- 6c
\large =- 5a + 14b- 5c
\large =- 5a + 13b- 6c