\[ y'(x)=\frac {1}{y(x)+\sqrt {3 x+1}+2} \] ✓ Mathematica : cpu = 0.311572 (sec), leaf count = 140
DSolve[Derivative[1][y][x] == (2 + Sqrt[1 + 3*x] + y[x])^(-1),y[x],x]
\[\text {Solve}\left [6 \sqrt {33} \tanh ^{-1}\left (\frac {3 y(x)+7 \sqrt {3 x+1}+6}{\sqrt {33} \left (y(x)+\sqrt {3 x+1}+2\right )}\right )+44 c_1=33 \left (\log \left (\frac {-3 \sqrt {3 x+1} y(x)^2-3 \left (3 x+4 \sqrt {3 x+1}+1\right ) y(x)+6 x \left (\sqrt {3 x+1}-3\right )-10 \sqrt {3 x+1}-6}{2 (3 x+1)^{3/2}}\right )+\log (12 x+4)\right ),y(x)\right ]\] ✓ Maple : cpu = 0.217 (sec), leaf count = 77
dsolve(diff(y(x),x) = 1/(y(x)+2+(3*x+1)^(1/2)),y(x))
\[\ln \left (\left (3 y \left (x \right )+6\right ) \sqrt {3 x +1}+3 y \left (x \right )^{2}-6 x +12 y \left (x \right )+10\right )-\frac {6 \sqrt {3 x +1}\, \arctanh \left (\frac {3 \sqrt {3 x +1}+6 y \left (x \right )+12}{\sqrt {99 x +33}}\right )}{\sqrt {99 x +33}}-c_{1} = 0\]