Help ASAP

Select all the following that are quadratic equation.
( ) 5x^2+15x=0
( ) 6x-1=4x+7
( )x^2-4x=4x+7
( ) 2x-1=0
( ) 3x^2+5x-7=0
( ) x^3-2x^2+1=0

right answers only please do not waste my time cause 20 points are quite good