x^2+9x/x^2+3x+x^2-9/x^2+6x+9_其他解答

x^2+9x/x^2+3x+x^2-9/x^2+6x+9

人气：489 ℃　时间：2020-02-23 07:50:54

解答

=x(x+9)/x(x+3)+(x+3)(x-3)/(x+3)²
=(x+9)/(x+3)+(x-3)/(x+3)
=(x+9+x-3)/(x+3)
=2(x+3)/(x+3)
=2