The two angles form a straight line which is equal to 180 degrees. This makes the angles supplemtary.
To find x, add the two angles together to equal 180:
7x + x+20 = 180
Combine like terms:
8x + 20 = 180
Subtract 20 from both sides:
8x = 160
Divide both sides by 8:
X = 20
Answer:
x < -7
Step-by-step explanation:
-4x > 28
-x > 7
x < -7
The answer should be 5 or -5