First let's add 6x to both sides. We do this because the 6x is negative and by adding 6x to both sides, we are isolating the 11 and we are also making the 6x positive, which makes things easier later.
-6x + 11 = -7
+6x +6x
11 = -7 + 6x
Now let's flip the equation to make it easier to read:
-7 + 6x = 11
And let's add 7 to both sides as we need to isolate the 6x. We are adding 7 because the 7 is negative.
6x = 18
And finally to get the value of x we divide both sides by 6:
x = 3
I hope this helped, and have a great night! :)