Final answer:
The given differential equation (y - x²)dx + (x + y²)dy = 0 is solved by verifying that it is an exact equation, then integrating and combining the results to find the general solution yx - (1/3)x³ + (1/3)y³ = C, where C is a constant.
Step-by-step explanation:
The differential equation given is:
(y - x²)dx + (x + y²)dy = 0
 
To solve this first-order differential equation, we'll attempt to see if it is an exact equation. An exact differential equation is in the form M(x,y)dx + N(x,y)dy = 0, where ∂M/∂y = ∂N/∂x.
 
In our given equation: 
 - M(x,y) = y - x²
  - N(x,y) = x + y²
  
 
The partial derivatives are: 
 
Since ∂M/∂y equals ∂N/∂x, the equation is exact. 
Now, we integrate M with respect to x to find the function Φ(x,y):
∫ (y - x²) dx = yx - (1/3)x³ + f(y)
 
And we integrate N with respect to y to find the function Φ(x,y): 
∫ (x + y²) dy = xy + (1/3)y³ + g(x)
 
From these two equations, we can determine that Φ(x,y) = yx - (1/3)x³ + (1/3)y³ = C, where C is a constant. 
This is the general solution to the differential equation.