Bonjour
1) (x + 1) (x - 2) + 4
= x² - 2x + x - 2 + 4
= x² - x + 2
2) 3 (x - 1)² - 2x
= 3 (x² - 2x + 1) - 2x
= 3x² - 6x + 3 - 2x
= 3x² - 8x + 3
3) - (x + 1) (x - 1) + 1
= - (x² - 1) + 1
= - x² + 1 + 1
= - x² + 2
4) 3 (x - 1) - (x + 7) + 5 (x - 3)
= 3x - 3 - x - 7 + 5x - 15
= 3x + 5x - x - 3 - 7 - 15
= 7x - 25.
