(x-3) (x+4) = 4- (2x-1)²
links ausmultiplizieren, rechts 2. binomische Formel , zusammenfassen:
x2 + x = - 4·x2 + 4·x + 15 | + 4x2 | - 4x | -15
5x2 - 3x -15 = 0 | : 5
x2 - 3/5 x - 3 = 0
x2 + px + q = 0
pq-Formel: p = - 3/5 ; q = - 3
x1,2 = - p/2 ± \(\sqrt{(p/2)^2 - q}\)
x1,2 = 3/10 ± \(\sqrt{(3/10)^2 + 3}\)
x1 = 3/10 - √309/10 , x2 = 3/10 + √309/10
x1 ≈ -1.457839583 , x2 ≈ 2.057839583
Gruß Wolfgang