Bonjour,
2)
A = 6 (3x - 2) + 3 (4 - 5x)
A = 6 (3 * (- 2) - 2) + 3 (4 - 5 * (- 2))
A = 6 (- 6 - 2) + 3 (4 + 10)
A = 6 (- 8) + 3 (14)
A = - 48 + 42
A = - 6
3)
B = 5 (2x - 3) + 2 (7 - 4x)
B= 10x - 15 + 14 - 8x
B = 10x - 8x - 15 + 14
B = 2x - 1
4)
C = (x - 2) (3x + 5) + (x - 2) (4x - 7)
C = (x - 2) (3x + 5 + 4x - 7)
C = (x - 2) (7x - 2)