Question

resolver las operaciones indicadas a) 4(a^2+3)-(a^2+4)(a^2+2)-9a

Answer 1

4(a²+3)-(a²+4)(a²+2)-9a =

= 4a²+12-(a⁴+2a²+4a²+8)-9a=
= 4a²+12-a⁴-2a²-4a²-8-9a  =
= -a⁴+4a²-2a²-4a²-9a-8 =
= a⁴-2a²-9a-8.