Select all of the following that are quadratic equations.

Answer:
x^2 -2x = 4x+1
2x^2 +12x = 0
9x^2 +6x -3=0
Step-by-step explanation:
A quadratic equation has the highest power of x being squared
x^2 -2x = 4x+1
2x^2 +12x = 0
9x^2 +6x -3=0
These are all quadratic equations