My computer Hasse k560D-I7D2 . notebook with double graphic . HD 4600 and GTX850M

my problem is . it looks like we can't use GTX850M . It is default HD 4600 and can't be disabled in BIOS .

Could anyone can help with this problem ?

the followed was what i tried .

1. install GTX850 Driver . and can't be in gnome . so i rm /etc/X11/xorg.conf . then GTX 850 can't be workable .

2. i installed HD 4600 driver for linux .

thanks