Question

check whether the
following are quadratic equation
(x-3) (2 x + 1) = x (2x+5)​

Answer 1

Answer:

(i)

( x - 3 ) ( 2x + 1 )

2x^2 + x - 6x + 3

2x^2 - 5x + 3

hence it is a quadratic equation

(ii)

x ( 2x + 5 )

2x^2 + 5x

Hence it is a quadratic equation

Hope it helps to you!!

Answer 2

$\tt{(x - 3)(2x + 1) = x(2x + 5)} \\ \tt{x(2x + 1) - 3(2x + 1) = 2 {x}^{2} + 5x} \\ \tt{2 {x}^{2} + x - 6x - 3 = 2 {x}^{2} + 5x } \\ \tt{ - 5x - 3 = 5x} \\ \tt{ - 10x = 3} \\ \tt{x = \frac{ - 3}{10} }$

It's not in the form of quadratic equation.

Therefore it's not a quadratic equation.