How do you solve #|3b - 3| \leq 12#?

1 Answer
Sep 27, 2017

#-3<=b<=5#

Explanation:

Consider these condition:

#|-13|=+13 >12#

From this scenario we can deduce you may not have any value of #3b-3# that is less than #-12#

In the same way we may not have any value of #3b-3# that is greater than +12

Consider these points as limiting the range such that we have:

#-12<=3b-3<=12#

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Consider the lower bound (-12)

Set #" "3b-3=-12color(white)("ddd") =>color(white)("ddd") b=(3-12)/3=-3#

So #color(white)("dd")3b-3>=-12color(white)("ddd")=>color(white)("dddd")b>=(3-12)/3#

#color(white)("ddddddddddddddddddd")=>color(white)("dddd")b>=-3#

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Consider the upper bound (+12)

Set#color(white)("d")3b-3=+12color(white)("dddd")=>color(white)("dddd")b=(12+3)/3=+5#

So#color(white)("d")3b-3=<=12color(white)("dddd")=>color(white)("dddd")b<=(12+3)/3#

#color(white)("ddddddddddddddddddd")=>color(white)("dddd")b<=+5#

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#-3<=b<=5#

Tony B