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Mathematics 20 Online
OpenStudy (fanduekisses):

**CHECK MY WORK PWEASE?? **Am I doing this right? SOLVING INEQUALITY.

OpenStudy (fanduekisses):

\[\frac{ 3 }{ x-1 }+\frac{ 2x}{ x+1 }>-1\]

OpenStudy (fanduekisses):

\[\frac{ 3(x+1)+2x(x-1)+(x-1)(x+1) }{ (x-1)(x+1) } >0\]

OpenStudy (fanduekisses):

\[\frac{ 3x^2+x-2 }{ (x-1)(x+1) }\]

OpenStudy (fanduekisses):

I did a sign chart but I get all positive, I know I must've done something wrong because the answer is \[(-\infty, -1) U (1,\infty)\]

OpenStudy (fanduekisses):

I did a sign chart but I get all positive, I know I must've done something wrong because the answer is \[(-\infty, -1) U (1,\infty)\]

OpenStudy (fanduekisses):

@countonme123 @dan815 @Data_LG2

OpenStudy (misty1212):

HI!!

OpenStudy (misty1212):

there is some mistake here, lets see if we can find it

OpenStudy (fanduekisses):

:)

OpenStudy (misty1212):

first lets check the algebra

OpenStudy (fanduekisses):

ok

OpenStudy (misty1212):

ooh i see it!!

OpenStudy (misty1212):

your numerator is wrong you wrote \[\frac{ 3x^2+x-2 }{ (x-1)(x+1) }\] but it should be \[\frac{ 3x^2+x+2 }{ (x-1)(x+1) }\]

OpenStudy (fanduekisses):

Ohhhhhh I see it now too lol

OpenStudy (misty1212):

now the numerator in this case is always positive so you can ignore it

OpenStudy (misty1212):

and \[(x+1)(x-1)>0\] outside the zeros, on \(x<-1\) and \(x>1\)

OpenStudy (fanduekisses):

So I only look at x=+1 then

OpenStudy (misty1212):

zeros are at \(1\) and \(-1\)

OpenStudy (fanduekisses):

Thank you! :D

OpenStudy (fanduekisses):

I have another question, how do you find the domain of a function that has a fraction inside a square root? As in:\[f(x)=\sqrt{\frac{ x }{ x^2-2x-35 }}\]

OpenStudy (fanduekisses):

I factored the denominator: (x-7)(x+5)

OpenStudy (fanduekisses):

so x cannot equal 7 or -5

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