# How to solve this differential equation

Number 65 in http://www.math.ucsb.edu/mathclub/GRE/GRE8767.pdf asks to find the graphs possible curves that satisfy the differential equation

$(\frac{dy}{dx})^2 + 2y \frac{dy}{dx} + y^2 = 0$

What method is used to solve this differential equation?

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The given equation can be rewritten as: $$\left( \frac{dy}{dx} + y \right)^2 = 0.$$