Adjust brightness on Lubuntu 16.04 - Ask Ubuntu

i adjust backlight. there trying use

sudo apt-get install -y xbacklight [sudo] password ubuntu:  reading package lists... done building dependency tree        reading state information... done xbacklight newest version (1.2.1-1build1). 0 upgraded, 0 newly installed, 0 remove , 2 not upgraded. 

without success. follows graphic-card , driver:

01:00.0 vga compatible controller [0300]: nvidia corporation g73 [geforce 7600 gt] [10de:0391] (rev a1)     kernel driver in use: nouveau     kernel modules: nvidiafb, nouveau 

and here comes current settings brightness , resolution:

gamma:      1.0:1.0:1.0 brightness: 1.0 screen 0: minimum 320 x 200, current 1920 x 1200, maximum 4096 x 4096 vga-1 disconnected (normal left inverted right x axis y axis) lvds-1 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 470mm x 300mm 

i deinstalled backlight , using te command:

sudo bash -c "echo 1 > /sys/class/backlight/apple_backlight/brightness; 

to set baklight "1". can use integer in range 1 15.