What type of polynomial equation is 5x³ + 9x² - 4 = 0?

Question: Which of the following is the polynomial equation 5x³ + 9x² - 4 = 0

Solution:
The given polynomial equation is in terms of x.
The highest power of x is 3 and hence the degree of the equation is 3.
Hence, it is a cubic equation.

The highest degree of the polynomial is 2 is a quadratic equation.
The highest degree of the polynomial is 1 is a linear equation.
The highest degree of the polynomial is 4 is a biquadratic equation.