bonjour
1. 7 x * 3 x = 21 x²
2. 6 x + 5 x = 11 x
3. 7 x² + 3 x + 11
4. 12 x² + 28 x
5. 10 x² - 6 x
6. 8 x² + 20 x + 6 x + 15 = 8 x² + 26 x + 15
7. 15 x - 21 x² + 5 - 7 x = - 21 x² + 8 x + 5
8 . 10 x + 15 - ( 2 x + 6 - x² - 3 x ) = 10 x + 15 - 2 x - 6 + x² + 3 x = x² + 11 x + 9
