Which of the following is not a quadratic equation?
Correct Answer: Option(d)
Solution: A. 2(x+1)2=4x2+2x+1 2(x2+2x+1)=4x2+2x+1 2x2+4x+2=4x2+2x+1 2x2+4x+2−4x2−2x−1=0 −2x2+2x+1=0 is a quadratic equation B. 2x+x2=2x2+5 −x2+2x=5 is a quadratic equation C. [2x3]2+x2=3x2+5x (6x2)+x2−3x2−5x=0 4x2−5x=0 is a quadratic equation D. (x2+2x)2=x5+4x3+3 As degree of x is 5, it is not quadratic.