Tentukan jumlah dari : a) 6p - 5q - 2r dan -8p + 6q + 9r b) 8x² + 4x -21 dan 6x² - 14x +7 c) 2 (3a + 5b + 3) dan 4 (2b - 3a + 6)

a)
6p - 5q - 2r + (-8p + 6q + 9r)
= 6p - 5q - 2r - 8p + 6q + 9r
= 6p - 8p - 5q + 6q - 2r + 9r
= -2p + q + 7r

b)
8x² + 4x - 21 + (6x² - 14x + 7)
= 8x² + 4x - 21 + 6x² - 14x + 7
= 8x² + 6x² + 4x - 14x - 21 + 7
= 14x² - 10x - 14

c)
2(3a + 5b + 3) + 4(2b - 3a + 6)
= 6a + 10b + 6 + 8b - 12a + 24
= 6a - 12a + 10b + 8b + 6 + 24
= -6a + 18b + 30

a. 6p + (-8p) - 5q + 6q - 2r +9r = -2p + q + 7r
b. 8x^2 + 6x^2 + 4x +(-14x) - 21 +7 = 14x^2 - 10x -14
c. 6a - 12a + 10b +8b + 6 +24 = -6a + 18b + 30