Question

Check whether the following is the quadratic equation: 

(x – 3)(2x + 1) = x(x + 5)

Answer 1

(x - 3)(2x + 1) = x(x + 5)

⇒ 2x² - 5x - 3 = x² + 5x

⇒  x² - 10x - 3 = 0

It is of the form ax² + bx + c = 0.

Hence, the given equation is quadratic equation.