bonsoir
x² + 12 x = 45
x² + 12 x - 45 = 0
Δ = 12 ² - 4 ( 1 * - 45 ) = 144 + 180 = 324 = 18 ²
x 1 = ( - 12 - 18 ) / 2 = - 30 /2 = - 15
x 2 = ( - 12 + 18 ) / 2 = 6 /2 = 3
S ( - 15 ; 3 )
x² + 4 x - 32 = 0
Δ = 16 - 4 ( 1 * - 32 ) = 16 + 128 = 144 = 12 ²
x 1 = ( - 4 - 12 ) / 2 = - 16 /2 = - 8
x 2 = ( - 4 + 12 ) / 2 = 8/2 = 4
S ( - 8 ; 4 )
