-2(6+s)>-15-2s
First step is to distribute. Multiply -2 by everything inside the parentheses.
-12 - 2s > -15 - 2s
Now add 2s to both sides.
-12 > -15
Now divide both sides by -1, and remember to switch the sign because you divided by a negative number.
12 < 15
This has infinite solutions.
