Treat the inequality just like any other equation where you solve for x only with inequalities, when you divide by a negative number you MUST flip the inequality sign (look at the work in the picture to see what I mean).
Because the graphs go in opposite directions the interval notation will have “union” in it represented by “u”.
General rules:
< > : empty circle. parentheses for interval notation
-∞, ∞: parentheses
<=,>= (greater/less than or equal to): filled in circle. brackets for interval notation