Jawabanmu

2014-09-03T19:36:11+07:00
(5x - 6y + 8z) + (7x - 9z) - (2y + 9z - 10)
= 5x - 6y + 8z + 7x - 9z - 2y - 9z - 10
= 5x + 7x - 6y - 2y +8z - 9z - 9z +10
= 12x - 8y - 10z + 10
2014-09-03T19:45:26+07:00
(5x - 6y + 8z ) + ( 7x - 9z ) - ( 2y + 9z - 10 )
= 5x - 6y + 8z + 7x -9z - 2y - 9z + 10
= 5x + 7x - 6y - 2y + 8z - 9z - 9z + 10
= 12x - 8y - 10z + 10