here's another i can't solve. t - 5√t - 14 = 0 i added 14 to both sides and then squared them. then i minused 196 and am left with t^2 + 15t -196 = 0 this doesn't work, what have i done wrong?
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Originally Posted by Miasmagasma here's another i can't solve. t - 5√t - 14 = 0 i added 14 to both sides and then squared them. then i minused 196 and am left with t^2 + 15t -196 = 0 this doesn't work, what have i done wrong?
Originally Posted by skeeter cheers but why did my method not work?
Originally Posted by Miasmagasma cheers but why did my method not work? Because . If you post all your working on how you got that (wrong) result your error(s) can be explained.
Originally Posted by mr fantastic Because . If you post all your working on how you got that (wrong) result your error(s) can be explained. well i thought t times 5√t = 5t which is no doubt wrong. how do you work that out?
Last edited by mr fantastic; December 9th 2009 at 07:30 PM. Reason: Moved new question to new thread
Originally Posted by Miasmagasma here's another i can't solve. t - 5√t - 14 = 0 i added 14 to both sides and then squared them. then i minused 196 and am left with t^2 + 15t -196 = 0 this doesn't work, what have i done wrong? Notice it looks very much like a quadratic. So use a dummy variable . This would mean . Your equation becomes or . Note that, since , the solution is unusable. This means, since , that .
Originally Posted by Miasmagasma well i thought t times 5√t = 5t which is no doubt wrong. how do you work that out? How can ? If t = 4 do you get a correct result from this? And what then do you think is equal to?
As you surmised, . On the other hand, .
Last edited by NOX Andrew; December 10th 2009 at 05:21 PM.
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