Répondre :
bonjour
- x² + 40 x - 300 = 0
Δ = 40 ² - 4 ( - 1 * - 300 ) = 1 600 - 1 200 = 400
x 1 = ( - 40 - 20 ) / - 2 = - 60 / - 2 = 30
x 2 = ( - 40 + 20 ) / - 2 = - 20 / - 2 = 10
- ( x - 30 ) ( x - 10 )
bonjour
- x² + 40 x - 300 = 0
Δ = 40 ² - 4 ( - 1 * - 300 ) = 1 600 - 1 200 = 400
x 1 = ( - 40 - 20 ) / - 2 = - 60 / - 2 = 30
x 2 = ( - 40 + 20 ) / - 2 = - 20 / - 2 = 10
- ( x - 30 ) ( x - 10 )