[tex] {3x}^{2} - 5x = - 8 \\ {3x}^{2} - 5x + 8 = 0[/tex]
This equation has the next form:
[tex] {ax}^{2} + bx + c = 0[/tex]
To find if the equation has two complex solutions we have to check if the discriminant is negative, as follows:
[tex] {b}^{2} - 4ac \\ ( { - 5})^{2} - 4 \: . \: 3 \: . \: 8 = 25 - 96 = - 71 < 0[/tex]
Then, the first case has two complex solutions.
In the second case,
[tex] {2x}^{2} = 6x - 5 \\ {2x}^{2} - 6x + 5 = 0[/tex]
The discriminant in this case is:
[tex]( { - 6})^{2} - 4 \: . \: 2 \: . \: 5 = 36 - 40 = - 4 < 0[/tex]
Then, the second case has two complex solutions.
In the third case,
[tex]12x = {9x}^{2} + 4 \\ { - 9x}^{2} + 12x - 4 = 0[/tex]
The discriminant in this case is:
[tex] {12}^{2} - 4 \: . \: ( - 9) \: . \: ( - 4) = 144 - 144 = 0[/tex]
Then, the third case has two real solutions.
In the fourth case,
[tex] { - x}^{2} - 10x = 34 \\ { - x}^{2} - 10x - 34 = 0[/tex]
The discriminant in this case is:
[tex]( { - 10})^{2} - 4 \: . \: ( - 1) \: . \: ( - 34) = 100 - 136 = - 36 < 0[/tex]
Then, the fourth case has two complex solutions.
