Dash Posted October 4, 2010 Report Share Posted October 4, 2010 4/x-7 + 9/x-4 = 7/x2-11x+28 The slashes mean that its a fraction and the x2 means its x to the power 2. I've been at this problem for a while and can't seem to get it. Quote Link to comment Share on other sites More sharing options...
Guru Posted October 4, 2010 Report Share Posted October 4, 2010 So..(4/x)-7 + (9/x)-4 = (7/x2)-11x+28 Is that how it is? You really should put parenthesis so we know how the problem looks. Quote Link to comment Share on other sites More sharing options...
Newman Posted October 4, 2010 Report Share Posted October 4, 2010 4/(x-7) + 9/(x-4) = 7/(x^2-11x+28) seems to make more sense. Quote Link to comment Share on other sites More sharing options...
Dash Posted October 4, 2010 Author Report Share Posted October 4, 2010 4/(x-7) + 9/(x-4) = 7/(x^2-11x+28) seems to make more sense. Yeah thats it. Sorry about that. Quote Link to comment Share on other sites More sharing options...
Cleveland's Finest Posted October 4, 2010 Report Share Posted October 4, 2010 13 = 7x^2-28x-196 / (x^2-11x+28) I multiplied out the two bottom halves on the left side so now you've got to deal with it on one side. Then multiply the dividend on the right side by 13 and see where that takes you. 1 Quote Link to comment Share on other sites More sharing options...
Newman Posted October 4, 2010 Report Share Posted October 4, 2010 Well I got: 4/(x-7) + 9/(x-4) = 7/(x-7)(x-4) so cancel out the bottom half of the fractions by cross-multiplying. 4x-16 + (9x-63) = 7 13x - 86 = 0 x = 86/13 Kinda unsure about this answer since x resulted in a fraction though. 1 Quote Link to comment Share on other sites More sharing options...
SRV Posted October 4, 2010 Report Share Posted October 4, 2010 (edited) mathway.com Enjoy, it helps me a lot when I am unsure about a problem. yes, the answer is 86/13 Edited October 4, 2010 by SRV 1 Quote Link to comment Share on other sites More sharing options...
Dash Posted October 4, 2010 Author Report Share Posted October 4, 2010 13 = 7x^2-28x-196 / (x^2-11x+28) I multiplied out the two bottom halves on the left side so now you've got to deal with it on one side. Then multiply the dividend on the right side by 13 and see where that takes you. Well I got: 4/(x-7) + 9/(x-4) = 7/(x-7)(x-4) so cancel out the bottom half of the fractions by cross-multiplying. 4x-16 + (9x-63) = 7 13x - 86 = 0 x = 86/13 Kinda unsure about this answer since x resulted in a fraction though. Thank you!! 86/13 was actually one of the answer choices. Quote Link to comment Share on other sites More sharing options...
YugoRocketsFan Posted October 4, 2010 Report Share Posted October 4, 2010 Myalgebra.com ftw, you just type your problem in and it automatically does it for you. 1 Quote Link to comment Share on other sites More sharing options...
Dash Posted October 4, 2010 Author Report Share Posted October 4, 2010 mathway.com Enjoy, it helps me a lot when I am unsure about a problem. Thanks, looks like a decent site. I will check this out later tonight Quote Link to comment Share on other sites More sharing options...
fish7718 Posted October 4, 2010 Report Share Posted October 4, 2010 (edited) well first u gotta get common demonators so u get 4x-16 / (x-7)(x-4) + 9x-63 / (x-7)(x-4) = 7 / (x-7)(x-4) then 4x+9x = 13x-16 + -63 = 47 so 13x-47 = 7 then +47 to both sides 13x=54 x = 54/13 EDIT: oops added my negs wrong didn't I? Haven't take a math course in 3 years jeez so -16 + -63 would be -79 13x-79=7 add 79 to both sides 13x = 86 x= 86/13 Newman got it Edited October 4, 2010 by STATCity 1 Quote Link to comment Share on other sites More sharing options...
Newman Posted October 4, 2010 Report Share Posted October 4, 2010 Cool, it's good to know I have not lost my maths skills because of the holidays considering my most important exams are in 3 weeks. Quote Link to comment Share on other sites More sharing options...
Dash Posted October 4, 2010 Author Report Share Posted October 4, 2010 Myalgebra.com ftw, you just type your problem in and it automatically does it for you. Wow that site is PERFECT for double checking your answers. I might even buy the package so I can see the steps, could be a life saver later in the year. This thread really helped out a lot. Thanks everyone. Quote Link to comment Share on other sites More sharing options...
SRV Posted October 4, 2010 Report Share Posted October 4, 2010 I actually just did this stuff 2 weeks ago, are you taking college algebra? Quote Link to comment Share on other sites More sharing options...
Dash Posted October 4, 2010 Author Report Share Posted October 4, 2010 I actually just did this stuff 2 weeks ago, are you taking college algebra? Yep. It was one of the problems on my test review due tomorrow. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.