Question

Which of these is a quadratic equation?
1) x²− = x²+ 2
2) None
3) ( + 1)( + 3) = ( − 1)( − 4)
4) ( + 1) = 2 − 3​

Answer 1

3 is the answer because the equation which has four values or constant or variables is known as quadratic equation.

Answer 2

A quadratic equation is an equation that can be rearranged in standard form where X represent unknown and A,B and C are known number. where a is not equal to zero if a equal to zero then it is linear equation not quadratic equation