Solve for x. The solutions in interval notation are of the form (a, b). State a. (Enter an exact number.)

abs(3 x + 15) < 30

1 answer

|3x+15| < 30

case 1:
3x+15 < 30
3x < 15
x < 5

case 2:
-(3x+15) < 30
3x+15 > -30
3x > -45
x > -15

so, the solution set is (-15,5), as shown here:

http://www.wolframalpha.com/input/?i=|3x%2B15|+%3C+30