Firefox and Chromium too slow - Adobe Flash related

Hello, I think I need and update of Adobe Flash, however I don't see it in the "update managger", both my browsers Firefox and Chromium are slow in sites that flash is required, specially in Facebook, It is a headache to try to brows it.
I know from previous experience that if I tried to update flash from Firefox it will say , "it is already in the system", on Chromium I have dowloaded "flash_player_ppapi_linux.x86_64.tar.gz" but I don't know how to install, I am not advance in linux.

What shall I do ?

This is my computer. Thanks in advanced

Code:

System:    Host: sil-MS-7529 Kernel: 4.13.0-39-generic x86_64 (64 bit)
           Desktop: Xfce 4.12.3 Distro: Zorin 12 xenial
Machine:   Mobo: MICRO-STAR model: G31TM-P21 (MS-7529) v: 1.0
           Bios: American Megatrends v: V4.7 date: 07/28/2010
CPU:       Dual core Pentium E5300 (-MCP-) cache: 2048 KB
           clock speeds: max: 2603 MHz 1: 1209 MHz 2: 1216 MHz
Graphics:  Card: Intel 82G33/G31 Express Integrated Graphics Controller
           Display Server: X.Org 1.19.5 drivers: intel (unloaded: fbdev,vesa)
           Resolution: 1360x768@60.02hz
           GLX Renderer: Mesa DRI Intel G33 GLX Version: 1.4 Mesa 17.2.8
Audio:     Card-1 Intel NM10/ICH7 Family High Definition Audio Controller
           driver: snd_hda_intel
           Card-2 VIA VT1720/24 [Envy24PT/HT] PCI Multi-Channel Audio Controller
           driver: snd_ice1724
           Sound: Advanced Linux Sound Architecture v: k4.13.0-39-generic
Network:   Card: Realtek RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller
           driver: r8169
           IF: enp2s0 state: down mac: <filter>
Drives:    HDD Total Size: 610.2GB (49.0% used)
           ID-1: /dev/sda model: WDC_WD400BB size: 40.0GB
           ID-2: /dev/sdb model: SAMSUNG_HD322HJ size: 320.1GB
           ID-3: USB /dev/sdc model: 2500BMV_External size: 250.1GB
Partition: ID-1: / size: 29G used: 9.9G (38%) fs: ext4 dev: /dev/sdb1
           ID-2: /home size: 262G used: 97G (39%) fs: ext4 dev: /dev/sdb5
           ID-3: swap-1 size: 4.10GB used: 0.00GB (0%) fs: swap dev: /dev/sdb6
RAID:      No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors:   System Temperatures: cpu: 47.0C mobo: N/A
           Fan Speeds (in rpm): cpu: N/A
Info:      Processes: 186 Uptime: 1:44 Memory: 1197.7/3936.0MB
           Client: Shell (bash) inxi: 2.2.35


Hi, launch Synaptic Package Manager and search for 'flashplugin-installer'.

thanks , it is already installed , today I got an update of firefox from "update managger"