How do you solve #-5\leq \frac { - 2x + 5} { 3} \leq 3#?

1 Answer
Feb 18, 2017

See the entire solution process below:

Explanation:

First, multiply each segment of the system of inequalities by #color(red)(3)# to eliminate the fraction and keep the system balanced:

#color(red)(3) xx -5 <= color(red)(3) xx (-2x + 5)/3 <= color(red)(3) xx 3#

#-15 <= cancel(color(red)(3)) xx (-2x + 5)/color(red)cancel(color(black)(3))) <= 9#

#-15 <= -2x + 5 <= 9#

Next, subtract #color(red)(5)# from each segment of the system to isolate the #x# term while keeping the system in balance:

#-15 - color(red)(5) <= -2x + 5 - color(red)(5) <= 9 - color(red)(5)#

#-20 <= -2x + 0 <= 4#

#-20 <= -2x <= 4#

Now, divide each segment of the system by #color(blue)(-2)# to solve for #x# while keeping the system balanced. However, because these are inequalities and we are multiplying or dividing the system by a negative term we must reverse the inequality signs:

#(-20)/color(blue)(-2) color(red)(>=) (-2x)/color(blue)(-2) color(red)(>=) 4/color(blue)(-2)#

#10 color(red)(>=) (color(blue)(cancel(color(black)(-2)))x)/cancel(color(blue)(-2)) color(red)(>=) -2#

#10 >= x >= -2#