The equation 3x + 4 = 0 is a linear equation, not a quadratic one. A quadratic equation must have the form ax² + bx + c = 0, where a ≠ 0 and the highest exponent of the variable x is 2. In this case, the highest exponent of x is 1, so it is not quadratic.Let me know if you need more help! If this helps, feel free to mark it Brainliest