Hello,
We know that all the angles shown add up to 360 (think of a circle).
We also know that the angle of (6x-1)° is congruent to the angle opposite of it. (the "top left" angle) = 6x - 1°
We also know that the angle of (7x-1)° is congruent to the angle opposite of it.
(the "bottom left" angle) = 7x -1°
Knowing the sum of all angles as well as the angle measures in terms of x, we can add all the angle measures and equal it to 360.
So, we get (7x - 1) + (7x - 1) + (6x - 1) + (6x - 1) = 360
Simplify and we get:
26x - 4 = 360
Add 4 to both sides to get 26x = 364
Divide by 26 on both sides to get 14.
x = 14
Hope this helps!
we have
Solve the inequality
Multiply by 
both sides-----> remember change inequality sign
the solution is the interval-----------> (-∞,-8]
using a graph tool
see the attached figure
the solution is the shaded area
