Răspuns:
1.
a = 2
b = -5
c = -2
2.
a = 2.5
b = -3
c = 0
3.
a = -1
b = 4
4.
b = -1
5.
a = 3
b = 0
c = 2
6.
x² - x - 2 = 0
7.
-4x² + 4x = 0
8.
[tex] \sqrt{2} {x² \div + 4x = 0}^{?} [/tex]
9.
-x² + 2x - 3 = 0
