A second degree equation in one variable x of the form

• ax³ +  bx + c = 0

• ax⁴ + bx

• ax² + bx + c = 0

• ax + b

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Explanation: A second degree equation in one variable x is an equation of the form:

ax² + bx + c = 0

It is called a quadratic equation because it has the variable x raised to the second power (or squared).

ax³ +  bx + c = 0 is a third degree equation, which is also known as a cubic equation, because it has the variable x raised to the third power (or cubed).

ax⁴ + bx is a fourth degree equation, which is also known as a quartic equation, because it has the variable x raised to the fourth power.
ax + b is a first degree equation, which is also known as a linear equation, because it has the variable x raised to the first power (or not raised at all).