Bonsoir
E = ( 3 x - 1 )² - ( 2 x - 3 )²
1. E = 9 x² - 6 x + 1 - ( 4 x² - 12 x + 9 ) = 9 x² - 6 x + 1 - 4 x² + 12 x - 9 = 5 x² + 6 x - 8
2. E = ( 3 x - 1 + 2 x - 3 ) ( 3 x - 1 - 2 x + 3 ) = ( 5 x - 4 ) ( x + 2 )
pour x = √ 2
5 ( √2)² + 6 √2 - 8 = 10 + 6 √2 - 8 = 2 + 6 √2
E = 0
( 5 x - 4 ) ( x + 2 ) = 0
x = 4/5 ou - 2
