Sagot :
bonjour
f (x) = ( 2 x - 8 ) ( x + 6 )
f (x) = 2 x² + 12 x - 8 x - 48
f (x) = 2 x² + 4 x - 48
2 x² + 4 x - 48 = 0
Δ = 16 - 4 ( 2 * - 48 ) = 16 + 384 = 400 = 20 ²
x 1 = ( - 4 - 20 ) / 2 = - 24 /2 = - 12
x 2 = ( - 4 + 20 ) /2 = 16 /2 = 8
bonjour
f (x) = ( 2 x - 8 ) ( x + 6 )
f (x) = 2 x² + 12 x - 8 x - 48
f (x) = 2 x² + 4 x - 48
2 x² + 4 x - 48 = 0
Δ = 16 - 4 ( 2 * - 48 ) = 16 + 384 = 400 = 20 ²
x 1 = ( - 4 - 20 ) / 2 = - 24 /2 = - 12
x 2 = ( - 4 + 20 ) /2 = 16 /2 = 8