Bonsoir,
a. (5x + 7)(x - 3) - (x - 3)(x + 2)
= (x - 3)[(5x + 7) - (x + 2)]
= (x - 3)(5x + 7 - x - 2)
= (x - 3)(4x + 5)
b. (x - 3)(2x - 5) + 2x - 6
= (x - 3)(2x - 5) + 2(x - 3)
= (x - 3)[(2x - 5) + 2]
= (x - 3)(2x - 5 + 2)
= (x - 3)(2x - 3)
c. (x - 3)² + x - 3
= (x - 3)(x - 3) + 1(x - 3)
= (x - 3)[(x - 3) + 1]
= (x - 3)(x - 3 + 1)
= (x - 3)(x - 2)
d. (x + 3)(x - 3) - 5(x - 3)
= (x - 3)[(x + 3) - 5]
= (x - 3)(x + 3 - 5)
= (x - 3)(x - 2)
