Mathematics
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OpenStudy (angela210793):
2^(a-b)=6
2^(a+b)=12 find b=?
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OpenStudy (anonymous):
well just try logarithm?
OpenStudy (anonymous):
log2,6=a-b
log 2,12=a+b
OpenStudy (anonymous):
wait i take my notebook and my pencil ^^
OpenStudy (angela210793):
Can we do it like this:
2^(a-b)=6
-----------=2^(a-b-a-b)=1/2
2^(a+b)=12
2^-2b=1/2
2^-2b=2^-1
-2b=-1
b=1/2
OpenStudy (angela210793):
I don't think we need log....
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OpenStudy (anonymous):
m2 just its a way ...
OpenStudy (amistre64):
you can do that since the bottom w know dont equal 0
OpenStudy (angela210793):
kk thnx ^_^
@Amistre can u pls look 1 of my q?
OpenStudy (amistre64):
which one?
OpenStudy (anonymous):
its simple
2^a - 2^b = 6
2^a + 2^b=12
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OpenStudy (angela210793):
this 1:
What should m be so that :
(m+3)x^2-5mx+4m+1>0 for every x...
OpenStudy (anonymous):
and now its 2 x 2^a = 18 ^^
OpenStudy (angela210793):
Korcan 2^(a-b)=2^a/2^b
OpenStudy (amistre64):
(m+3)x^2 +(-5m) x + (4m +1) > 0 its a quad that needs to be accounted for a b and c
OpenStudy (amistre64):
\[x = 0; when;x=\frac{5m \pm \sqrt{25m^2 -4(m+3)(4m+1)}}{2(m+3)}\]
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OpenStudy (amistre64):
we can narrow down the results by working the discriminate
OpenStudy (angela210793):
yea i found this 2..but i can't go any further...O.o
OpenStudy (anonymous):
u see u are better then me...
OpenStudy (angela210793):
right..:P same story :P
OpenStudy (amistre64):
25m^2 -4m^2 -16m -12 >= 0
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OpenStudy (amistre64):
21m^2 -16m -12 >= 0 ; quad form that to see your options
OpenStudy (angela210793):
tht's it? Thnx ^_^ :)
OpenStudy (anonymous):
well angela can you help me on my question?
OpenStudy (angela210793):
hmmmm..idk..let me see
OpenStudy (amistre64):
the roots to that are:
m= \[\frac{2}{21}(4\pm \sqrt{79})\]
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OpenStudy (amistre64):
...... i missques the discriminate when I did that :/
OpenStudy (angela210793):
Sorry but i need some english lessons too..wht's missques? O.o