Which among the following is a quadratic equation?
A. (x + 1 )² = x² – 1
B. (x + 1 ) (x – 2 ) = x – 3
C. x (x + 1 )²= 0
D. 2x² = 2 ( x – 1)²
with explanation pls...

B.

Because when doing the math, letter B fits the criteria of a quadratic equation. Which is ax^2 + bx + c = 0.

A is wrong because if we were to do the math, there would be no ax^2. The most important thing in a quadratic equation is the term ax^2, bx and c do not matter as much.

C is wrong because there cannot be a greater exponent than ^2.

D is wrong because of the same reason as letter a.