Mathematics
7 Online
OpenStudy (mathmath333):
solve
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OpenStudy (mathmath333):
\(\large \color{black}{\begin{align} |x-3|+|x+4|+|x-1|=14\hspace{.33em}\\~\\
\end{align}}\)
OpenStudy (alekos):
I get x = 14/3 and -14/3
OpenStudy (alekos):
Is this a test?
OpenStudy (mathmath333):
how get that
OpenStudy (mathmath333):
this is no test
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OpenStudy (alekos):
well first we take all the positive values within the modulus
(x-3) + (x+4) + (x-1) =14 and solve for x
OpenStudy (anonymous):
best way to do this problem is partitioning the x's
OpenStudy (alekos):
then we take all the negative values
-(x-3) - (x+4) - (x-1) =14 and solve for x
OpenStudy (mathmath333):
there will be total of 6 cases but that is a long way
OpenStudy (alekos):
if you plot the graph you'll see that there are only two values
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OpenStudy (mathmath333):
that can be if 4 values are not valid
OpenStudy (alekos):
that's right. the 4 values are not valid
OpenStudy (alekos):
just plot the graph and you'll see
OpenStudy (mathmath333):
i look for a pen paper method
OpenStudy (alekos):
that's fine, you can do it that way. But Desmos is easier
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Parth (parthkohli):
Hey, yes, just do it casewise.
OpenStudy (mathmath333):
u mean take 6 cases ?
Parth (parthkohli):
You'd need five, so yes.
OpenStudy (mathmath333):
how is it 5 cases
OpenStudy (anonymous):
It's 4 cases
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Parth (parthkohli):
Oh, four.
Parth (parthkohli):
|dw:1434037874987:dw|
Parth (parthkohli):
For some reason, I thought there were four absolute values. Oops.
OpenStudy (anonymous):
|dw:1434037949803:dw|