bonjour
[tex]x^{2} + 4 x - 1 = ( x - 1 ) ( x - 2 ) \\\\\\ x^{2} + 4 x - 1 = x^{2} - 2 x - x + 2 \\\\x^{2} - x^{2} + 4 x+ 2 x + x = 2 + 1 \\\\6 x = 3\\x = 2[/tex]
( x - 2 )² = ( x + 3 )²
[tex]x^{2} - 4 x + 4 = x^{2} + 6 x + 9 \\x^{2} - x^{2} - 4 x - 6 x = 9 - 4 \\\\\\- 10 x = 5\\x = - 5/10 = - 1 /2[/tex]
( x + 7 )² = x² - 49
[tex]x^{2} + 14 x + 49 = x^{2} - 49\\\\x^{2} - x^{2} + 14 x = - 49 - 49\\14 x = - 98\\x = - 98/14 = - 14[/tex]
