How do you solve #2| x | - 4< 14#?

1 Answer
smendyka
May 2, 2017

See the entire solution process below:

Explanation:

First, add #color(red)(4)# to each side of the inequality to isolate the absolute value term while keeping the inequality balanced:

#2abs(x) - 4 + color(red)(4) < 14 + color(red)(4)#

#2abs(x) - 0 < 18#

#2abs(x) < 18#

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

#(2abs(x))/color(red)(2) < 18/color(red)(2)#

#(color(red)(cancel(color(black)(2)))abs(x))/cancel(color(red)(2)) < 9#

#abs(x) < 9#

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

#-9 < x < 9#

Or

#x > -9# and #x < 9#

Or, in interval notation:

#(-9, 9)#

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