Multiply by 0.4 on both sides to cancel the original 0.4 and change the 10
9 represents the event, 13 represents all possible events.
I have a bag of 13 marbles. 9 of my marbles are blue, 4 are red. My probability of reaching in and pulling out a blue marble at random is 9/13 (Which is 69%)
ANSWER
{x|x < -2 or x > 8}
EXPLANATION
The given absolute inequality is
By the definition of absolute value,
Multiply through the second inequality by -1 and reverse the inequality sign
Simplify
Divide through by 2