Given,
⇒(x−2)(x+6)5(x+6)−3(x−2)=x4⇒x2+6x−2x−125x+30−3x+6=x4⇒x2+4x−122x+36=x4⇒x(2x+36)=4(x2+4x−12)⇒2x2+36x=4x2+16x−48⇒4x2−2x2+16x−36x−48=0⇒2x2−20x−48=0⇒2(x2−10x−24)=0⇒x2−10x−24=0⇒x2−12x+2x−24=0⇒x(x−12)+2(x−12)=0⇒(x+2)(x−12)=0⇒x=−2 or x=12.
Hence, value of x = -2 or 12.