Answer: x = 22
Step-by-step explanation:
The adjacent angle to the right of the (6x+1) angle is 180-(6x+1). Simply subtract it from 180 to get its supplementary counterpart.
The three inner angles of any triangle must add to 180, so,
(inner angle 1) + (inner angle 2) + (inner angle 3) = 180
[ 180-(6x+1) ] + (79) + (2x+10) = 180
180 - 6x - 1 + 79 + 2x + 10 = 180
(-6x+2x) + (180-1+79+10) = 180
-4x+268 = 180
-4x = 180 - 268
-4x = -88
x = -88/(-4)
x = 22