A differential equation is exact if you can integrate the right-hand side and the left-hand side directly. This is the simplest type of differential equations. Rule Exact Differential Equations y′ = f(x) ⇒ y = ∫ f(x)dx + C Example 1 Solve the differential equation y′ = 1 x + 2x y = ∫ y′dx = ∫ 1 x + 2xdx = ln |x| + x2 + C y = ∫ y′dx = ∫ 1 x + 2xdx = ln |x| + x2 + C