1) 16a - 9a = (16-9)a = 7a
2) 3b + 12b - 16b = (3+12-16)b = -b
3) 15c - 12 + 5c = (15+5)c - 12 = 20c - 12
4) 15x - 8x - 12x = (15-8-12)x = -5x
1) 16a - 9a = (16-9)a = 7a
2) 3b + 12b - 16b = (3+12-16)b = -b
3) 15c - 12 + 5c = (15+5)c - 12 = 20c - 12
4) 15x - 8x - 12x = (15-8-12)x = -5x