Pe x^2-4x + 3 = x^2-3x -x + 3 =( x^2-x) -3(x-1) = x(x-1) -3(x-1) =( x-3)(x-1) ; = (x-3)(x+3)/(x-1)(x-3). + (x+2)/(x+1) -(x^2+5x+2)/x-1)(x+1)= (x+3)/(x-1) + (x+2) /(x+1) -(x^2+5x+2)/(x-1)(x+1) = [(x+3)(x+1)+ (x+2)(x-1) -x^-5x-2]/(x-1)(x+1) = ( X^2+x+3x+1+ x^2-x+2x-2-x^2-5x-2)/(x-1)(x+1) = x^2-1/(x^2-1)= 1
