Find all real numbers $x$ such that $3x - 7 \le 5x +9$. Give your answer as an interval
3x -7 <= 5x + 9
-2x <= 16
x <= -8
The solution in interval notation is (-inf,-8].
...ooops ! Remember when dealing with inequalities, when you divide or multiply both sides by a negative the < or > symbol reverses !