How do you solve abs(2b + 9) = 0?

1 Answer
Alan P.
Jun 21, 2016

b=-4 1/2

Explanation:

In general if abs(2b+9)=k
then
color(white)("XXX"){: ("either",,"or",), (,2b+9=-k,,2b+9=+k) :}
but
when k=0 these mean the same thing.

So
color(white)("XXX")2b+9=0

color(white)("XXX")2b=-9

color(white)("XXX")b=-4 1/2

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