how do i do this problem, do i add -15 to each side, leaving t by itself making the answer -.01
e^(-0.15t) = 0.14
This is the same as:
1 / (e^(3t/20)) = 7/50
1 = (e^(3t/20) * 7/50
50/7 = e^(3t/20)
ln(50/7) = 3t/20
20ln(50/7) = 3t
20ln(50/7)/3 = t
This is hard to put into a simpler form, it depends how you want it to be.
You could put 20 and 3 into the logarithm or make it the difference of two logarithms.
ln((50/7)^20/3) = t
No...what you have to do is take the ln of both sides, then the (-.15t) that is now an exponent becomes a coefficient on the left side like so:
lne^(-.15t) = ln(.14)
(-.15t)lne = ln(.14) since lne = 1 this becomes now
-.15t = ln(.14) dividing by -.15 gives
t = ln(.14)/(-.15) = -ln(.14)/(.15)
im pretty sure but its been a while u take the lne of both sides so:
e^(-.15t)=lne.14
-.15t=lne.14 (you should figure this number out on the calculator then continue from there)
divide both sides by -.15 which leaves you with the value of t
you might check this its been a while
You take the natural log of both sides denoted ln, ln(e)=1 so the steps are
1.natural log both sides
2.Laws of logarithms says move exponents to front as Multipliers
3.ln(e)= 1
4.Divide both sides by -.15
.e^(-.15t)=.14
1 .ln(e^(-.15t)=ln.14
2 -.15t(ln(e)=ln.14
3 (-.15t)(1)=ln.14
4 t= ln.14/-.15
ln EVERYTHING!!!
so lne^-.15t=ln(.14)
and the ln of e becomes its power. so -.15t=ln.14
and divide by -.15 so it becomes t = -(ln(.14))/(.15)
um use natural log...
ln(.14) = -.15t
grab a calculator
at least i think thats how u do it
snaps to all of you........ my brain doesn't work like this.
Comments
e^(-0.15t) = 0.14
This is the same as:
1 / (e^(3t/20)) = 7/50
1 = (e^(3t/20) * 7/50
50/7 = e^(3t/20)
ln(50/7) = 3t/20
20ln(50/7) = 3t
20ln(50/7)/3 = t
This is hard to put into a simpler form, it depends how you want it to be.
You could put 20 and 3 into the logarithm or make it the difference of two logarithms.
20ln(50/7)/3 = t
ln((50/7)^20/3) = t
No...what you have to do is take the ln of both sides, then the (-.15t) that is now an exponent becomes a coefficient on the left side like so:
lne^(-.15t) = ln(.14)
(-.15t)lne = ln(.14) since lne = 1 this becomes now
-.15t = ln(.14) dividing by -.15 gives
t = ln(.14)/(-.15) = -ln(.14)/(.15)
im pretty sure but its been a while u take the lne of both sides so:
e^(-.15t)=lne.14
-.15t=lne.14 (you should figure this number out on the calculator then continue from there)
divide both sides by -.15 which leaves you with the value of t
you might check this its been a while
You take the natural log of both sides denoted ln, ln(e)=1 so the steps are
1.natural log both sides
2.Laws of logarithms says move exponents to front as Multipliers
3.ln(e)= 1
4.Divide both sides by -.15
.e^(-.15t)=.14
1 .ln(e^(-.15t)=ln.14
2 -.15t(ln(e)=ln.14
3 (-.15t)(1)=ln.14
4 t= ln.14/-.15
ln EVERYTHING!!!
so lne^-.15t=ln(.14)
and the ln of e becomes its power. so -.15t=ln.14
and divide by -.15 so it becomes t = -(ln(.14))/(.15)
um use natural log...
ln(.14) = -.15t
grab a calculator
at least i think thats how u do it
snaps to all of you........ my brain doesn't work like this.