[[_homogeneous, `class G`], _rational, [_Abel, `2nd type`, `class B`]]
Book solution method
Exact equation, integrating factor
Mathematica ✓
cpu = 0.0108369 (sec), leaf count = 68
Maple ✓
cpu = 0.02 (sec), leaf count = 33
DSolve[x*(x^3 + y[x])*y'[x] == (x^3 - y[x])*y[x],y[x],x]
Mathematica raw output
{{y[x] -> x^4/(-x + Sqrt[1 + x^4*C[1]]/Sqrt[x^(-2)])}, {y[x] -> -(x^4/(x + Sqrt[
1 + x^4*C[1]]/Sqrt[x^(-2)]))}}
Maple raw input
dsolve(x*(x^3+y(x))*diff(y(x),x) = (x^3-y(x))*y(x), y(x),'implicit')
Maple raw output
ln(x)-_C1+1/2*ln(y(x)/x^3)-1/4*ln((x^3+2*y(x))/x^3) = 0