Respuesta:
[tex]\text{\left(-9a²b³+7a²b-6\right)+\left(12a³b²-9a²b-5\right)}[/tex][tex]\mathrm{\left(-9a^2b^3+7a^2b-6\right)+\left(12a^3b^2-9a^2b-5\right)}[/tex]
[tex]\mathrm{-9a^2b^3+7a^2b-6+12a^3b^2-9a^2b-5}[/tex]
[tex]\mathrm{-9a^2b^3+7a^2b-9a^2b+12a^3b^2-6-5}[/tex]
[tex]\mathrm{-9a^2b^3+7a^2b-9a^2b+12a^3b^2-11}[/tex]
[tex]\mathrm{\:7a^2b-9a^2b=-2a^2b}[/tex]
Solución:
[tex]\boxed{\mathrm{-9a^2b^3-2a^2b+12a^3b^2-11}}[/tex]
Saludos...
