1. **Stating the problem:**
Solve the differential equation:
$$x^{2} (y + a)^{2} (y' - 1) = y^{2} - 2ax^{2} y + a^{2}$$
where $y' = \frac{dy}{dx}$.
2. **Rewrite the equation:**
Expand the right side and isolate $y'$:
$$x^{2} (y + a)^{2} (y' - 1) = y^{2} - 2ax^{2} y + a^{2}$$
Divide both sides by $x^{2} (y + a)^{2}$:
$$y' - 1 = \frac{y^{2} - 2ax^{2} y + a^{2}}{x^{2} (y + a)^{2}}$$
3. **Simplify the numerator:**
Notice that:
$$y^{2} - 2ax^{2} y + a^{2} = (y - a x)^{2}$$
Check:
$$(y - a x)^{2} = y^{2} - 2 a x y + a^{2} x^{2}$$
But the original numerator is $y^{2} - 2 a x^{2} y + a^{2}$, which is not the same. So this factorization is incorrect.
Instead, keep numerator as is.
4. **Rewrite $y'$:**
$$y' = 1 + \frac{y^{2} - 2 a x^{2} y + a^{2}}{x^{2} (y + a)^{2}}$$
5. **Try substitution:**
Let $z = y + a$, then $y = z - a$ and $y' = z'$.
Rewrite numerator:
$$y^{2} - 2 a x^{2} y + a^{2} = (z - a)^{2} - 2 a x^{2} (z - a) + a^{2}$$
Expand:
$$(z - a)^{2} = z^{2} - 2 a z + a^{2}$$
So numerator becomes:
$$z^{2} - 2 a z + a^{2} - 2 a x^{2} z + 2 a^{2} x^{2} + a^{2}$$
Combine like terms:
$$z^{2} - 2 a z - 2 a x^{2} z + a^{2} + 2 a^{2} x^{2} + a^{2} = z^{2} - 2 a z (1 + x^{2}) + a^{2} (1 + 2 x^{2})$$
6. **Rewrite denominator:**
$$x^{2} (y + a)^{2} = x^{2} z^{2}$$
7. **Rewrite $y'$ in terms of $z$:**
$$z' = 1 + \frac{z^{2} - 2 a z (1 + x^{2}) + a^{2} (1 + 2 x^{2})}{x^{2} z^{2}}$$
8. **Separate terms:**
$$z' = 1 + \frac{z^{2}}{x^{2} z^{2}} - \frac{2 a z (1 + x^{2})}{x^{2} z^{2}} + \frac{a^{2} (1 + 2 x^{2})}{x^{2} z^{2}}$$
Simplify:
$$z' = 1 + \frac{1}{x^{2}} - \frac{2 a (1 + x^{2})}{x^{2} z} + \frac{a^{2} (1 + 2 x^{2})}{x^{2} z^{2}}$$
9. **Final form:**
$$z' = 1 + \frac{1}{x^{2}} - \frac{2 a (1 + x^{2})}{x^{2} z} + \frac{a^{2} (1 + 2 x^{2})}{x^{2} z^{2}}$$
This is a nonlinear first order ODE in $z$.
Further solution would require advanced methods or numerical approaches.
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**Summary:** We transformed the original equation into an ODE for $z = y + a$:
$$z' = 1 + \frac{1}{x^{2}} - \frac{2 a (1 + x^{2})}{x^{2} z} + \frac{a^{2} (1 + 2 x^{2})}{x^{2} z^{2}}$$
This form is suitable for further analysis or numerical solution.
Differential Equation A53Fe3
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