计算：x^2+9x/x^2+3x加上x^2-9/x^2+6x+9 解方程：2x/2x-5加上5/5+2x=1

(x²+9x)/(x²+3x) +(x²-9)/(x²+6x+9)
=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)
=(2x+6)/(x+3)
=2(x+3)/(x+3)
=2

2x/(2x-5) +5/(5+2x)=1
去分母，等式两边同乘以(2x-5)(5+2x)
2x(5+2x)+5(2x-5)=(2x-5)(5+2x)
整理，得
20x=0
x=0
代入分式方程检验，分母均不等于0，x=0是分式方程的解。
x=0

x^2+9x/x^2+3x加上x^2-9/x^2+6x+9 =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解方程：2x/2x-5加上5/5+2x=12x(2x+5)+5(2x-5)=4x²-254x²+10x+10x-25=4x²-2520x...