[math](1/2ab^2)(-8/5a^2b)-2a^2b^2(-4ab)-2/5a(-5/3a^2)(+3b^3)[/math]
[math]-4/5a^3b^3+8a^3b^3+2/3a^3(+3b^3)[/math]
[math]-4/a^3b^3+8a^3b^3+2a^3b^3[/math]
[math]-4/5a^3b^3+(8+2)a^3b^3[/math]
[math]-4/5a^3b^3+10a^3b^3[/math]
[math](-4+50)/5a^3b^3[/math]
[math]+46/5a^3b^3[/math]
