Question

Find which of the following equations are quadratic:

$\left(A\right)$ $(3x-1{)}^2=5(x+8)$

Answer 1

Step : Finding whether the given equation is quadratic or not :

The standard form of a quadratic equation
is $a{x}^2+bx+c=0$, where a,b and c are all real numbers and $a\ne 0.$

Given equation is

$(3x-1{)}^2=5(x+8)$

$\Rightarrow 9x^2+1-6x=5x+40$

$[\because (a-b{)}^2=a^2+b^2-2ab]$

$\Rightarrow 9x^2-6x-5x-40+1=0$

$\Rightarrow 9x^2-11x-39=0;$

The given equation is of the form $a{x}^2+bx+c=0$

$\therefore$ Given equation is a quadratic equation.