Bonjour, pouvez-vous m’aider svp ?

Salut,
x^2-5x+6 =0 => ∆ =25-4(1x6) = 15-24 = 1
x^2-4x+4 = 0 => ∆ = 16-4(1x4) = 16-16 = 0
x^2-x -1 = 0 => ∆ = 1-4(-1x-1) = 1+4 = 5
2x^2-8x = 0 => ∆ = 64-4(2x-10) = 64+80 = 144
5x^2+2x+1 = 0 => ∆ = 4-4(-5x1) = 4+20 = 24
3x^2/2 - 4x + 2,5 = 0 => ∆ = 16-4(3/2x 2,5) = 16-3,75 = 12,25
Bon courage.