超简单分式计算,送分,在线求助[(x^2+9x)/(x^2+3x)]+[(x^2-9)/(x^2+6x+9)]要有过程才加10分

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超简单分式计算,送分,在线求助
[(x^2+9x)/(x^2+3x)]+[(x^2-9)/(x^2+6x+9)]
要有过程才加10分

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

[(x^2+9x)/(x^2+3x)]+[(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)
=(2x+6)/(x+3)
=2(x+3)/(x+3)
=2

[x(x+9)/x(x+3)]+[(x+3)(x-3)/(x+3)^2] =[(x+9)/(x+3)]+[(x-3)/(x+3)]=2

x^2+9x=x(x+9)
x^2+3x=x(x+3)
消去x,为: x+9/x+3
x^2-9=(x+3)(x-3)
x^2+6x+9=(x+3)(x+3)
消去(x+3)为: x-3/x=3
2者相加 2x+6/x+3 =2