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mathmath333
 one year ago
solve for \(x\)
mathmath333
 one year ago
solve for \(x\)

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mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0\(\large \color{black}{\begin{align} x^25x+8>0\hspace{.33em}\\~\\ \end{align}}\)

misty1212
 one year ago
Best ResponseYou've already chosen the best response.2work in cases solve if \(x<\frac{8}{5}\) and if \(x>\frac{8}{5}\)

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0i worked m onfised

misty1212
 one year ago
Best ResponseYou've already chosen the best response.2if \(x>\frac{8}{5}\) then \[5x+8=5x+8\] right ?

misty1212
 one year ago
Best ResponseYou've already chosen the best response.2if it is not clear how i got that say so and i will explain

misty1212
 one year ago
Best ResponseYou've already chosen the best response.2the absolute value is a piece wise function

misty1212
 one year ago
Best ResponseYou've already chosen the best response.2let me write it as one hold on

misty1212
 one year ago
Best ResponseYou've already chosen the best response.2ok so if \(5x+8>0\) then \(5x+8=5x+8\) and \(5x+8>0\) if \(x>\frac{8}{5}\) so case 1:\(x>\frac{8}{5}\) you solve \[x^2(5x+8)>0\] or \[x^25x8>0\]

misty1212
 one year ago
Best ResponseYou've already chosen the best response.2once you solve that, the actual answer is the intersection of your solution and \(x>f\rac{8}{5}\) then repeat with \(x<\frac{8}{5}\) solving \[x^2+5x+8>0\]

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0\(\large \color{black}{\begin{align} x>\dfrac{5+\sqrt{57}}{2},\ x<\dfrac{5\sqrt{57}}{2} \hspace{.33em}\\~\\ \end{align}}\)

misty1212
 one year ago
Best ResponseYou've already chosen the best response.2intersection of your solution and \(x>\frac{8}{5}\)

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0lol m still confused

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0this is solution of \(x^25x8>0\) \(\large \color{black}{\begin{align} x>\dfrac{5+\sqrt{57}}{2},\ x<\dfrac{5\sqrt{57}}{2} \hspace{.33em}\\~\\ \end{align}}\)

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0for \(x^2+5x+8>0\) \(\large \color{black}{\begin{align} \infty<x<+\infty \hspace{.33em}\\~\\ \end{align}}\)

phi
 one year ago
Best ResponseYou've already chosen the best response.1You began by assuming x >= 8/5 = 1.6 you found either x <= 1.275 (roughly) so 1.6 <= x < 1.275 or x > 6.275 now you have to check the other condition, where x <= 8/5

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0for \(x<8.5\) \(\infty<x<8/5\)

phi
 one year ago
Best ResponseYou've already chosen the best response.1in other word, when (5x8) is negative, we can drop the absolute value sign, and negate the value inside. (for example, if we know we have a negative number, say 2 inside the abs value:  2  we know this is the same as  (2) = +2 ) so x^2  (5x+8)>0 or x^2 +5x+8> 0 complete the square x^2 + 5x +25/4 +8 > 25/4 (x+5/2)^2 > 25/4  8 or \[ (x+5/2)^2 > 7/4 \] which will be true for all x (the left side will be 0 or bigger for any x) but we assumed x <= 8/5 so the solution is x <= 8/5

phi
 one year ago
Best ResponseYou've already chosen the best response.1now combine 1.6 <= x < 1.275 or x > 6.275 and x<= 8/5 = 1.6 we get \[ \infty < x < \frac{5\sqrt{57}}{2} \text{ or } x >\frac{5+\sqrt{57}}{2} \]

phi
 one year ago
Best ResponseYou've already chosen the best response.1Does this stuff make sense? If you are missing some idea, you should ask.

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0no question , thnx

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0http://openstudy.com/study#/updates/5593fc3ae4b0989cc8780f4d

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0how do u approximate \(\sqrt{57}\) without calculater

phi
 one year ago
Best ResponseYou've already chosen the best response.1I don't. but I know its bigger than 7 (7*7= 49) and less than 8 (8*8=64)

phi
 one year ago
Best ResponseYou've already chosen the best response.1I only used decimals because it was easier to type (and easier to compare to 8/5)
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