.
Forget about the absolute value part for a second... if x + 3 < 5, then x must be less than 2, right? You can isolate x by subtracting 3 from both sides... x + 3 < 5 x < 2 But when x+3 is negative, then you do need to worry about the absolute value, since after the absolute value, it still must be less than 5. x must be larger than -8, because when you add 3, you need to get a number greater than -5 so the absolute value will make the whole thing less than 5. -8 < x < 2 It sounds confusing, but just try a couple x values above and below -8 and 2 to see how it makes the inequality work or not work.
I like to think of these this way: \[ \large |x + 3| < 5 \\ \ \\ \textrm{is the same as} \\ \ \\ \large x + 3 < 5 \ \textrm{and} \\ \large -(x+3) > 5\] This works because when
Join our real-time social learning platform and learn together with your friends!