Which of the following is not a quadratic equation?

Answer:
In this equation x² + 3x - 2 = x² - 2x is not a quadratic equation.
Step-by-step explanation:
The equation which contains x² term (In simplified form), then only we can apply quadratic formula.(i.e equation is quadratic)
A. ax² + bx = 0,
Yes , Since x² term is present here ,so we can use quadratic formula.
B. 3x² = -4x - 1
We can simplify this,
i.e 3x² + 4x + 1 = 0
Since x² term is present here ,so we can use quadratic formula.
C. x² = 5
Yes , Since x² term is present here ,so we can use quadratic formula.
D. x² + 3x - 2 = x² - 2x
We can simplify this,
x² - x² + 3x + 2x - 2 = 0
or 5x - 2 = 0
Since x² term is not here ,so we can not use quadratic formula.