$\"\"$

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The differential equation is $\"\"$ and $\"\"$ .

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Let $\"\"$ .

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Substitute $\"\"$ in the above equation.

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$\"\"$

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Consider $\"\"$

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Apply partial fraction.

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ then $\"\"$ .

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$\"\"$ .

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Substitute $\"\"$ and $\"\"$ in the partial differential equation.

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$\"\"$

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Integrate on each side

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$\"\"$

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Apply integral formula: $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ .

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Apply exponential on each side.

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$\"\"$

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$\"\"$

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Let $\"\"$ .

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$\"\"$

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Substitute $\"\"$ .

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$\"\"$

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Substitute $\"\"$ in the above equation.

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$\"\"$

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Substitute $\"\"$ in the $\"\"$

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$\"\"$ .

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The solution of differential equation is $\"\"$ .

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$\"\"$

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The solution of differential equation is $\"\"$ .