Răspuns:
E(x) = x/(x+4) - (2x+3)/(x-4) - (x²+10x-8)/(16-x²)
= x/(x+4) - (2x+3)/(x-4) - (x²+10x-8)/(4-x)(4+x)
= x/(x+4) - (2x+3)/(x-4) + (x²+10x-8)/(x-4)(x+4)
= [x(x-4) - (x+4)(2x+3) + x² + 10x - 8]/(x-4)(x+4)
= (x² - 4x - 2x² - 11x - 12 + x² + 10x - 8)/(x-4)(x+4)
= (-5x - 20)/(x-4)(x+4)
= - 5(x + 4)/(x-4)(x+4)
= - 5/(x - 4)