Can someone help me i don't understand this DE

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iScience
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problem: xy''-4y'=x^4

when i solve it i get y(homogeneous)=C1+C2x^5 which is fine because that's what the back of the book says

but for the particular solution, i get .. C1=-(1/25)x^5 , C2=(1/5)lnx

so y(general)= C1+C2x^5-(1/25)x^5+(1/5)lnx(x^5)

but wolframalpha as well as the back of my book both say the answer is...
y(general)=C1+C2x^5+(1/5)lnx(x^5)

where does the -(1/25)x^5 term go?...
 
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so technically my answer is correct and they just combined the x^5 terms.. i see
 
If you're finding the general solution of an ODE, then usually you would not allow pieces of the homogeneous solution to show up in the particular solution.