Mathematics
9 Online
OpenStudy (anonymous):
please, help me with this solve each exponential equation s:1.) e^x-2 = e^3x+1
2.) 7 = 6 + e^3-2x
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
\[e\large^x-2=e^{3x}+1\] or \[\large e^{x-2}=e^{3x}+1\]?
hartnn (hartnn):
lol, i guess
e^(x-2) = e^(3x+1)
OpenStudy (anonymous):
oh
OpenStudy (anonymous):
in that case i can do it
OpenStudy (anonymous):
please. thankyou so much
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
which one is it? there is some ambiguity here
hartnn (hartnn):
so, we just compare the exponents of 'e'
e^(x-2) = e^(3x+1)
so,
x-2 = 3x+1
can you find x from here ?
hartnn (hartnn):
lets assume the easiest one ;)
OpenStudy (anonymous):
yes, i end up solving there.
OpenStudy (anonymous):
is the second one
\[\large 7=6+e^{3-2x}\]?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
yep
OpenStudy (anonymous):
if so, subtract \(6\) and get
\[e^{3-2x}=1\] making
\[3-2x=0\]solve for \(x\)
OpenStudy (anonymous):
oh, okayy thanks! i got it
hartnn (hartnn):
since you are new here
\(\Huge \mathcal{\text{Welcome To OpenStudy}\ddot\smile} \)
OpenStudy (anonymous):
Thankyou! :)
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
why 3 - 2x = 0?
hartnn (hartnn):
\(e^0 = 1 \\ e^{3-2x}=1 \\ 3-2x = 0\)
hartnn (hartnn):
infact (anything except 0)^0 =1
OpenStudy (anonymous):
Ah, okayy Thanks! how about this one? (5/2)^x = 4/25
OpenStudy (anonymous):
please, if it's okay
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
i still find it hard
hartnn (hartnn):
hey, no problem at all :)
hartnn (hartnn):
4/25 = ...?
can you express 4 and 25 as powers of 2 and 5 ?
OpenStudy (anonymous):
2^2
OpenStudy (anonymous):
5^5
Join the QuestionCove community and study together with friends!
Sign Up
hartnn (hartnn):
so, 4/25 = (2/5)^2
agree ?
hartnn (hartnn):
5^5 ? O.o
OpenStudy (anonymous):
ayy, joke haha/ it's 5^2!
OpenStudy (anonymous):
^_^
hartnn (hartnn):
yes,
so (2/5)^2
but we have (5/2)^x on left
so,
Join the QuestionCove community and study together with friends!
Sign Up
hartnn (hartnn):
\(\Huge (\dfrac{2}{5})^2 = \dfrac{1}{(\dfrac{5}{2})^2}= (\dfrac{5}{2})^{-2}\)
got this ?
hartnn (hartnn):
there ?
OpenStudy (anonymous):
are you already a professor?
OpenStudy (anonymous):
Thanks. gonna take note with this
hartnn (hartnn):
i am a student just like you ^_^
Join the QuestionCove community and study together with friends!
Sign Up
hartnn (hartnn):
and could you find x there ?
OpenStudy (anonymous):
what year are you in?
OpenStudy (anonymous):
wait a minute
hartnn (hartnn):
i already completed my studies :)
OpenStudy (anonymous):
so ,the x on the first problem is -3/2? and the x on my second problem would be -2. ? is my answer correct?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
heyy heyy
hartnn (hartnn):
for 2nd problem.
3-2x = 0
right ?
x = 3/2
hartnn (hartnn):
ok
OpenStudy (anonymous):
for my question e^(x-2) = e^(3x+1) we end up at x -2 = 3x+1 , can u explain to me how we come up the answer of 1.5?
hartnn (hartnn):
its -1.5
x -2 = 3x+1
-2 = 2x +1
-2-1 = 2x
2x = -3
x=-3/2 = -1.5
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
ah, okay. really big thanks! is it really okay, i still have more questions
OpenStudy (anonymous):
:)
hartnn (hartnn):
i'll be glad to help :)