Hey there!!
Basic thing to know:
If you divide both the sides with a negative number, then, you switch the sides.
Given equation -
12 ≤ 4c - 3c + 10
First thing we got to do is combine all the like terms
12 ≤ c + 10
Now, subtract 10 on both sides
2 ≤ c
c ≥ 2
c is greater than or equal to 2
Hence c ≥ 2 , the values for c would become [ 2 , infinity ]
Hope my answer helps!