Tentukanlah hasil dari 5x-6y+8z+(7x-9z)-(2y+9z-10)

5x-6y+8z+(7x-9z)-(2y+9z-10)
= (5+7)x – (6+2)y – (9+9-8)z +10
= 12x -8y -10z -10
= 2(6x-4y-5z-5)