Question

Which of the following is a quadratic equation?

Options

• `x^2 + 2x + 1 = (4 - x)^2 + 3`

• `-2x^2 = (5 - x)(x - 2/5)`

• `(k + 1)x^2 + 3/2x` = 7, where k = –1

• `x^3 - x^2 = (x - 1)^3`

Answer 1

`x^3 - x^2 = (x - 1)^3`

Explanation:

The standard form of a quadratic equation is given by,

ax² + bx + c = 0, a ≠ 0

Given, x³ – x² = (x – 1)³

x³ – x² = x³ – 3x² + 3x – 1

2x² – 3x + 1 = 0

which represents a quadratic equation.