How do you solve #-9\leq \frac { 3x + 17} { 4} < 2#?

1 Answer
Oct 22, 2017

See a solution process below:

Explanation:

First, multiply each segment of the system of inequalities by #color(red)(4)# to eliminate the fraction while keeping the system balanced:

#color(red)(4) xx -9 <= color(red)(4) xx (3x + 17)/4 < color(red)(4) xx 2#

#-36 <= cancel(color(red)(4)) xx (3x + 17)/color(red)(cancel(color(black)(4))) < 8#

#-36 <= 3x + 17 < 8#

Next, subtract #color(red)(17)# from each segment to isolate the #x# term while keeping the system balanced:

#-36 - color(red)(17) <= 3x + 17 - color(red)(17) < 8 - color(red)(17)#

#-53 <= 3x + 0 < -9#

#-53 <= 3x < -9#

Now, divide each segment by #color(red)(3)# to solve for #x# while keeping the system balanced:

#-53/color(red)(3) <= (3x)/color(red)(3) < -9/color(red)(3)#

#-53/3 <= (color(red)(cancel(color(black)(3)))x)/cancel(color(red)(3)) < -3#

#-53/3 <= x < -3#

Or

#x >= -53/3# and #x < -3#

Or, in interval notation:

#[-53/3, -3)#