Posted by Es on .
I asked sue a question yesterday and don't understand the answer can you explain?
Here what it was
I think this question has a typo because none of the multiple choice answers fit.
The question is which of the following values is in the solution set of inequality 8-7x<-6?
A) -3 B)-2 C)2 D)-6
A if you plug in -3 you get
B) 8+14<-6 no
c) 8-14<-6 so -6<-6 no
D) 8+42<-6 no
Did I do something wrong or are there no correct answers?
•math - Ms. Sue, Thursday, December 27, 2012 at 6:44pm
-7x < -6 -8
-7x < -14
x = 2
SO WHEN SUE WROTE X=2 shouldn't it be
WHEN YOU SOLVE IT IS X<2
Then when you check it
-6<-6 IT DOESN'T WORK, PLEASE HELP ME UNDERSTAND HOW X=2 LIKE SUE SAID
X= 2 leads to -6 on both sides, so "2 is not in the solution set. Neither are the other choices.
You are correct.
C only works if < is replaced by </
let's just solve it ....
8 - 7x < -6
-7x < -14
divide by -7, remember that when we divide by a negative, the inequality sign has to be reversed, so
x > 2
obviously , only positives , so all those negatives can be ruled out
x = 2 does not satisfy x > 2
so there is no answer match-up in the given choices
Look again a the question
Is it it 8 - 7x ≥ -6 ?
if so, then x = 2 would be a solution.
It does not say xgreater than and equal to , so I believe the question is a misprint.