Question

T= ( x + 9) ( x - 9 ) -x ( x + 4 )

Answer 1

Pasos : ( x + 9 ) ( x - 9 ) - x ( x + 4 )

Desarrollar : ( x + 9 ) ( x - 9 ) : x^2 - 81

= x^2 - 81 - x ( x + 4 )

Desarrollar - x ( x + 4 ) : - x^2 - 4 x

= x^2 - 81 - x^2 - 4x

Simplificar :

= - 4x - 81

Answer 2

Respuesta:

(x+9)(x-9)-x(x+4)=T

-4x-81=T

-4x-81+81=T+81

-4x=T+81

$\frac{-4x}{-4}=\frac{T}{-4}+\frac{81}{-4}$

x= -$\frac{T+81}{4}$