Here's the question you clicked on:
FlyinSolo_424
Find the value of x: 2x^3 - 5x^2 - x + 20 = 0
would you like to go for a trignometric solution ?
I just need the value of x :o the answers have 2 x values. Its a whole different equation but Ive added everything and I just needed help on finding the x values of this because It confused me
what is the ans.?
if you want soln,,i can provide hint : see shubhamsrg's soln : http://openstudy.com/users/shubhamsrg#/updates/4fed5f8ae4b0bbec5cfcc1ac
first you have to convert the eqn into depressed but..
1: x= -4/3, x= -5 2: x= -4/3, x= 5 3:x= 4/3, x= -5 4:x= 4/3, x= 5
http://www.wolframalpha.com/input/?i=2x%5E3%2B-5x%5E2-x%2B20%3D0
I tried plugging it into wolframalpha already.. didnt work -_-
didn't work! there the ans. given is -1.6
Ok that gives me one answer but :o
I guess ill just try Plugging 5 and negative 5 into the original thing.. Thanks :p
Wait can Someone actually Help me? Cause Ive tried plugging the two 5's in but Its not equaling out. @Wired @JohnHanShanghai , the original equation is this,
|dw:1342092140095:dw|
have you tried 2 and minus 2?
But thats not a possible answer?
I think Im retarded because either 5 or -5 have to work . But I tried and of course I did something wrong
Wolfram says -4/3 and 5. Must've done something wrong when solving the equation.
there are 2 answers with -4/3
Wait where does it say 5?
http://www.wolframalpha.com/input/?i=%282%2F%28x-2%29%29%2B%287%2F%28x%5E2-4%29%29%3D5%2Fx
Well I didnt put int he original equation but thank you ! Again lol (:
The correct eq. is 3x^2-11x-20=0
\[\frac{2}{x-2}+\frac{7}{x^{2}-4}=\frac{5}{x}\] \[\frac{x+2}{x+2}*\frac{2}{x-2}+\frac{7}{x^{2}-4}=\frac{5}{x}\] \[\frac{2x+4+7}{x^{2}-4}=\frac{5}{x}\] \[2x^{2}+11x = 5x^{2}-20\] \[3x^{2}-11x-20 = 0\]
When in doubt, go back to the beginning :)