Bonsoir
4 - ( 2 x - 1 )² = - 5
4 - ( 4 x² - 4 x + 1 ) = - 5
4 - 4 x² + 4 x - 1 = - 5
- 4 x² + 4 x + 3 = - 5
- 4 x² + 4 x + 3 + 5 = 0
- 4 x² + 4 x + 8 = 0
Δ = ( 4 )² - 4 ( - 4 * 8 ) = 16 + 128 = 144 = 12²
x 1 = ( - 4 - 12 ) / - 8 = - 16 / - 8 = 2
x 2 = ( - 4 + 12 ) / - 8 = 8 / - 8 = - 1
S ( - 1 ; 2 )
