How do you solve #|b | - 2< 89#?

2 Answers
Sep 27, 2017

First, add #2# to both sides: #|b| < 91#.

So, we know that #b# is less than #91# and greater than #-91#.

Thus, #b# < 91 and b > -91.

#(-91, 91)#

Sep 27, 2017

See a solution process below:

Explanation:

First, add #color(red)(2)# to each side of the inequality to isolate the absolute value function while keeping the inequality balanced:

#abs(b) - 2 + color(red)(2) < 89 + color(red)(2)#

#abs(b) - 0 < 91#

#abs(b) < 91#

The absolute value function takes any term and transforms it to its non-negative form. Therefore, we must solve the term within the absolute value function for both its negative and positive equivalent.

#-91 < b < 91#

Or

#b > -91# and #b < 91#

Or, in interval notation:

#(-91, 91)#