E( x) = [ 1/ ( x - 2) - 2/ x + 1/ ( x + 2) ] : 4/ x • ( x² - 4)
E( x) = [ x( x + 2) - 2( x² - 4) + x( x + 2) ] / [ x( x - 2)( x + 2) ]
E( x) = ( x² + 2x - 2x² + 8 + x² - 2x ) / ( x³ - 4x )
E( x) = 8 / [ x( x² - 4) ] • x / 4 • ( x² -4)
E( x) = 2
Faci tu simplificările, spor!