Question

Select all that are quadratic equations
3x2+ 5x- 7 = 0
x3- 2x2+ 1 = 0
2x- 1 = 0
5x2+ 15x= 0
6x- 1 = 4x+ 7
x2- 4x= 4x+ 7

Answer 1

\[Standard ~ Form \]

\[ax^2 + bx + c = 0\]

Answer 2

http://www.mathsisfun.com/algebra/quadratic-equation.html

Answer 3

\[(variable)^2 \]

The squared part makes an equation quadratic.

Sometimes its easy to notice it or not, other times, you got to do some extra work since the equation gets a little more 'tricky'.

Answer 4

so all of them except for the 3rd one, 5th one, or 6th one