[_separable]
Book solution method
Separable ODE, Neither variable missing
Mathematica ✓
cpu = 0.043622 (sec), leaf count = 50
Maple ✓
cpu = 0.022 (sec), leaf count = 33
DSolve[x*(a + x)*y'[x] == y[x]*(b + c*y[x]),y[x],x]
Mathematica raw output
{{y[x] -> -((b*E^(b*C[1])*x^(b/a))/(c*E^(b*C[1])*x^(b/a) - (a + x)^(b/a)))}}
Maple raw input
dsolve(x*(a+x)*diff(y(x),x) = (b+c*y(x))*y(x), y(x),'implicit')
Maple raw output
1/b*c-(a+x)^(b/a)*x^(-b/a)*_C1+1/y(x) = 0