In der drittletzten Zeile muss es
4·x2- 25·x + 34 = 0 heißen | : 4
x2 - 25/4 x + 17/2 = 0
x2 + px + q = 0
pq-Formel: p = -25/4 ; q = 17/2
x1,2 = - p/2 ± \(\sqrt{(p/2)^2 - q}\)
x1,2 = 25/8 ± \(\sqrt{(25/8)^2-17/2 }\) = 25/8 ± \(\sqrt{81/64}\)
= 25/8 ± 9/8
x1 = 17/2 , x2 = 2