How do you solve #16= | 3m - 4| - 11#?

1 Answer
Jan 12, 2018

#-23/3# and #31/3#

Explanation:

#16 = abs(3m - 4) - 11#

#27 = abs(3m - 4#

Some people teach that "absolute value" means the number is positive, but that's not entirely accurate. Absolute value tells us how far the number is from 0 when we put it on the number line. There is no such thing as #- 14# feet or #- 8# meters.
So, a negative number or a positive number will yield the same value: # abs(-8) = abs(8) = 8#

So, we have two values to solve for

#27 = 3m - 4# and #-27 = 3m - 4#

#* * * * * * * * * * * #

#27 = 3m - 4#

#31 = 3m#

#m = 31/3#

#* * * * * * * * * * * #

#-27 = 3m - 4#

#-23 = 3m#

#m = -23/3#

So, we have two answers! And to check our work, let's graph the equation and see the #x#- intercepts

graph{y=abs(3x - 4)-27}

#-7.667# and #10.333#, which are the decimal approximations for

#-23/3# and #31/3#.

We were right! Nice work!