Before solving we need to remember the concept that adding or subtracting a number on both sides of the equation does not change the sign.
Now, let's take them one by one
A. x+6≤4
Subtracting 6 from both sides:
⇒x+6−6≤4−6
⇒x≤−2
B. x−8≥5
Adding 8 from both sides:
⇒x−8+8≥5+8
⇒x≥13
C. 9≤x+5
Subgtracting with 5 on both sides:
⇒9−5≤x+5−5
⇒4≤x
⇒x≥4
D. 6≤−8+x
Adding 8 on both sides:
⇒6+8≤−8+x+8
⇒14≤x
⇒x≥14