A quadratic equation is usually in the form:
[tex]ax^{2} +bx +c[/tex]
where a, b and c are the coefficients of the expression and a ≠ 0.
If a = 0, the equation becomes a linear expression and is no longer quadratic.
Hence, in the above options; y = 5x -2 is the only one that is not a quadratic equation.
