Explicație pas cu pas:
x²-4=(x+2)(x-2)
x²+4x+4=(x+2)²
x²-3x+2=x²-x-2x+2=x(x-1)-2(x-1)=(x-1)(x-2)
3x²+6x=3x(x+2)
x²-1=(x+1)(x-1)
E(x)=(x+2)(x-2)/(x+2)² *3x(x+2)/(x-1)(x-2) -6x/(x+1)(x-1)=>
E(x)=3x/(x-1)-6x/(x+1)(x-1)=>
E(x)=(3x²+3x-6x)/(x+1)(x-1)=>
E(x)=(3x²-3x)/(x+1)(x-1)=>E(x)=3x(x-1)/(x+1)(x-1)
=>E(x)=3x/(x+1)
