(x+5+9分之x-1)除以(x^2-4)/(x-1)
={(x+5)(x-1)+9}/(x-1)x (x-1)/(x^2-4)/
=(x^2+4x-5+9)x1/(x+2)(x-1)
=(x+2)^2/(x-2)(x+2)
=(x+2)/(x-2)