Answer:
11
[tex]9x {}^{2} + 9x + 28 = 0[/tex]
a= 9
b = 9
c = 28
12.
[tex]7x {}^{2} - 6x - 20 = 0[/tex]
a= 7
b = –6
c = –20
13.
[tex]x {}^{2} - 3x = 0[/tex]
a= 1
b = –3
c = 0
14.
[tex] - 2x {}^{2} + 5 = 0[/tex]
a= –2
b = 0
c = 5
15.
[tex] - 2x {}^{2} - 3x + 15 = 0[/tex]
a= –2
b = –3
c = 15
16.
[tex] - 4x {}^{2} + 3x - 8 = 0[/tex]
a= –4
b = 3
c = –8
17.
[tex]x {}^{2} - 3x - 10 = 0[/tex]
a= 1
b = –3
c = –10
18.
[tex]2x {}^{2} - 7x + 8 = 0[/tex]
a= 2
b = –7
c = 8
19.
[tex]x {}^{2} - 7x + 12 = 0[/tex]
a= 1
b = –7
c = 12
20.
[tex]x {}^{2} - x - 6 = 0[/tex]
a= 1
b = –2
c = –6
