Jawabanmu

2014-08-09T21:41:22+07:00
(5x-6y+8z) + (7x-9z) - (2y+9z-10) 
= (5x+7x) + (-6y-2y) + (8z-9z-9z) + 10
= 12x - 8y - 10z + 10
3 4 3