How do you solve and write the following in interval notation: #-7<b/9<0#?

1 Answer
Apr 4, 2018

See explanation.

Explanation:

To solve such double inequality you can use all methods used in standard inequalities only remembering to use them for all sides. Here you can multiply all sides by #9#:

#-7 < b/9 < 0# ##

After multiplying by #9# you get:

#-63 < b < 0#

The numbers fulfilling the inequality are greater than #-63# and smaller than #0#, so the solution can be written as:

#b in (-63;0)#