Question

Which of the following are quadratic equation in x? 

`(x+2)^3=x^3-8` 

Answer 1

`(x+2)^3=x^3-8` 

`⇒ x^3+6x^2+12x+8=x^3-8` 

`⇒6x^2+12x+16=0` 

This is of the form  `ax^2+bx+c=0`
Hence, the given equation is a quadratic equation.