bonjour
3 x² - 12 x + 10 = - 2
3 x² - 12 x + 10 + 2 = 0
3 x² - 12 x + 12 = 0
Δ = 144 - 4 ( 3 * 12 ) = 144 - 144 = 0
Δ = 0 donc une seule solution , = 12/6 = 2
2 x² + x - 1 = - 2
2 x² + x - 1 + 2 = 0
2 x² + x + 1 = 0
Δ = 1 - 4 ( 2 * 1 ) = 1 - 8 = - 7
Δ négatif donc pas de solution
- x² + 6 x = - 7
- x² + 6 x + 7 = 0
Δ = 36 - 4 ( - 1 * 7 ) = 36 + 28 = 64
x ₁ = ( - 6 - 8) / - 2 = 14/2 = 7
x ₂ = ( - 6 + 8 ) / - 2 = 2/2 = 1
- 4 x = 2 x² + 2
- 2 x² - 4 x - 2 = 0
Δ = ( - 4 )² - 4 ( - 2 * - 2) = 16 - 16 = 0
donc 1 seule solution = - 4/4 = - 1
x² + 0.5 x = 0.5
x² + 0. 5 x - 0.5 = 0
Δ = 0 .25 - 4 ( 1 * - 0.5) = 0.25 + 2 = 2.25
x ₁ = ( - 0.5 - 1.5 ) / 2 = - 2 /2 = - 1
x ₂ = ( - 0.5 + 1.5 ) / 2 = 1 /2
- 3 x² + 6 x = 3
- 3 x² + 6 x - 3 = 0
Δ = 36 - 4 ( - 3 * - 3 ) = 36 - 36 = 0
donc une seule solution = - 6 /- 6 = 1
