no puedo comertar mi potartil a wifi

En una terminal ejecuta sudo su y posteriormente da tu contraseña luego ejecuta lspci y copia todo el resultado que te de para ver como te podemos ayudar

muchas gracias
copie lo que me indicaste y te mando el resultado

acer@ubuntu:~$ sudo
usage: sudo [-D level] -h | -K | -k | -V
usage: sudo -v [-AknS] [-D level] [-g groupname|#gid] [-p prompt] [-u user
            name|#uid]
usage: sudo -l[l] [-AknS] [-D level] [-g groupname|#gid] [-p prompt] [-U user
            name] [-u user name|#uid] [-g groupname|#gid] [command]
usage: sudo [-AbEHknPS] [-r role] [-t type] [-C fd] [-D level] [-g
            groupname|#gid] [-p prompt] [-u user name|#uid] [-g groupname|#gid]
            [VAR=value] [-i|-s] [<command>]
usage: sudo -e [-AknS] [-r role] [-t type] [-C fd] [-D level] [-g
            groupname|#gid] [-p prompt] [-u user name|#uid] file ...
acer@ubuntu:~$ lspci
00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09)
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04)
00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 04)
00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b4)
00:1c.1 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 2 (rev b4)
00:1c.3 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 (rev b4)
00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation HM65 Express Chipset Family LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller (rev 04)
00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 04)
02:00.0 Network controller: Broadcom Corporation BCM43227 802.11b/g/n
03:00.0 Ethernet controller: Broadcom Corporation NetLink BCM57785 Gigabit Ethernet PCIe (rev 10)
03:00.1 SD Host controller: Broadcom Corporation NetXtreme BCM57765 Memory Card Reader (rev 10)
03:00.2 System peripheral: Broadcom Corporation Device 16be (rev 10)
03:00.3 System peripheral: Broadcom Corporation Device 16bf (rev 10)

Hola Marce, ¿ya intentaste activar el controlador privativo de Broadcom a través de la herramienta Software y actualizaciones (u Orígenes del software, como se conocía hasta Ubuntu 12.10)? En la pestaña «Controladores adicionales» te debe de salir la opción de activar ese controlador, si no, me dices. Saludos