mjhjmtu

I am trying to get to work my two monitor in debian9. I try several things and nothing get to work.
I have a new computer with two output, one VGA and the other HDMI. Both have a monitor conected and I see the same thing in both.
First I try the easy way that is to do it in:
system -> preference -> hardware -> monitors
And then there should be 2 monitors in the display but instead of that I get "monitor default unknown", and only one.
Then I try with "xrandr" and I get the error:

xrandr: Failed to get size of gamma for output default

This is the same problem as: Using two displays on debian

But I check and that answer is for debian8 and does not work in debian 9. Then I try to catch my output with lspci and I get:

00:00.0 Host bridge: Intel Corporation Device 3ec2 (rev 07)
00:02.0 VGA compatible controller: Intel Corporation Device 3e92
00:14.0 USB controller: Intel Corporation Device a36d (rev 10)
00:14.2 RAM memory: Intel Corporation Device a36f (rev 10)
00:16.0 Communication controller: Intel Corporation Device a360 (rev 10)
00:17.0 SATA controller: Intel Corporation Device a352 (rev 10)
00:1c.0 PCI bridge: Intel Corporation Device a33c (rev f0)
00:1c.7 PCI bridge: Intel Corporation Device a33f (rev f0)
00:1f.0 ISA bridge: Intel Corporation Device a303 (rev 10)
00:1f.3 Audio device: Intel Corporation Device a348 (rev 10)
00:1f.4 SMBus: Intel Corporation Device a323 (rev 10)
00:1f.5 Serial bus controller [0c80]: Intel Corporation Device a324 (rev 10)
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)

And I see there is no HDMI port found. So I don't know what is happening.
Does anybody know how can I solve this problem ?
Thanks.