SOLUTION: The solution for x-7<-12 is x<-5 . My text book recommends checking the solution by substituting -5 into the equation x-7=-12 to see if -5 is the correct boundary point, if -12=-12
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-> SOLUTION: The solution for x-7<-12 is x<-5 . My text book recommends checking the solution by substituting -5 into the equation x-7=-12 to see if -5 is the correct boundary point, if -12=-12
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Question 692859: The solution for x-7<-12 is x<-5 . My text book recommends checking the solution by substituting -5 into the equation x-7=-12 to see if -5 is the correct boundary point, if -12=-12 then -5 is the correct boundary point.
My question is this, why & where does the idea of plugging in -5 into x-7=-12 to see if it's the correct endpoint or boundary point come from? What does the equation have to do with the inequality???
Thanks
Ralph Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Since you get , my method is to
check by saying
This is true
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What they say is " For what value of does
the inequality begin to fail ?"
They could have said it fails for , but it also fails for , and also for
This approaches
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Also, they could say the inequality passes for , but also for also for
It does not pass when
Hope this helps
