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anonymous
 one year ago
Help for a medal, anyone?
I'm rusty on inequalities and need some help on a few problems to boost my memory.
Here's the first one...
9 < 4x + 8 < 10
anonymous
 one year ago
Help for a medal, anyone? I'm rusty on inequalities and need some help on a few problems to boost my memory. Here's the first one... 9 < 4x + 8 < 10

This Question is Closed

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2what are your thoughts ...

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0If I remember correctly, you're supposed to simplify the equation by adding, divining..etc terms on either side, but I'm not sure how to do that with an inequality.

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2the math doesnt change ... what you do to one part, you do to all the parts to keep them "equal" right?

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2in this case, the equation is in the middle instead of to the left or right ... what would you think we should do first?

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2just make a guess at what you think we should do to start with ... what comes to mind? 4x+8 is what we want to manipulate, how do we work about getting 'x' all by itself?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Would you solve one equality at a time like 9 < 4x + 8 or 4x + 8 < 10 ?

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2you can if you want, but i just work it all at once to avoid the extra work of writing it all out twice

amistre64
 one year ago
Best ResponseYou've already chosen the best response.29 < 4x + 8 < 10 8 8 8  17< 4x < 2

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ah, I see. Then you would divide all 3 parts by 4 to get x by itself.

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2correct, the only thing to watch out for is when we have to mulitply or divide by a negative number ... which they really should include the rule when doing equalities the sign reverses ... but we do not have to worry about that in this particular case do we

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2if a < b, then a > b if a > b, then a < b if a = b, then a = b ... the reversing of an equals sign just produces an equals sign, but it helps to make the rule consistent for all 3 equality signs.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So would 17/4 < x < 1/2 be the final answer or is there another step?

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2thats the answer for me, but im not grading it

amistre64
 one year ago
Best ResponseYou've already chosen the best response.217/4 cant be reduced, but it can be written as 4 and 1/4 if need be

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Okay, thank you. :) Could you help with one other? It looks a bit different from the first.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0\[\left\frac{ x+4 }{ 5 } \right < 6\]

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2absolute value, what does that mean to you?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I know that nothing inside of it can be negative (or at least that I recall)

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2first off 5 = 5 so we can go ahead and multiply thru by 5 x+4 < 30

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2it can be negative inside of it, but the bars cancel out the sign

amistre64
 one year ago
Best ResponseYou've already chosen the best response.230 = 30 and 30 = 30 when does x+4 = 30? or 30?

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2as a side note: a < k can be written as: k < a < k

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2x+4 < 30 can be written as 30 < x+4 < 30

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Then you just subtract 4 from both sides... 34 < x < 26 Also does the a < k or k < a < k rule always apply?

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2it is a rule, so it always applies yes. its just my brain that doesnt always remember it in time lol

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2\[\frac{x+4}{5}<6\] \[6<\frac{x+4}{5}<6\] \[306<x+4<30\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oh, okay. So 34 < x < 26 would be the answer correct?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Thank you so much for your help. :)

amistre64
 one year ago
Best ResponseYou've already chosen the best response.2youre welcome, and good luck :)
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