Solving 10^(x+3)=5e^(7-x): Need Help!

  • Thread starter Thread starter niteshadw
  • Start date Start date
AI Thread Summary
The discussion revolves around solving the equation 10^(x+3) = 5e^(7-x). The user initially attempts to apply logarithms but becomes stuck after rearranging the equation. A helpful response clarifies how to isolate x by moving all x terms to one side and constants to the other. The final solution is presented as x = (ln5 + 7 - 3ln10)/(ln10 + 1). The user expresses gratitude for the assistance in understanding the solution process.
niteshadw
Messages
20
Reaction score
0
I'm having a problem with a log question, its rather easy but I'm stuck after certain point.

The question is:

10^(x+3)=5e^(7-x)

I tried solving by:

ln10^(x+3) = ln5 + lne^(7-x)
(x+3)ln10 = ln5 + (7-x)

I am stuck after that, I've tried every combiantion and when I chack it with a calculator answer, my answer is different.

Any help would be much appreciated, thank you.
 
Physics news on Phys.org
(x+3)ln10 = ln5 + 7-x that is correct. Now just put all of the x's to the left hand side and all the rest on the other side : xln10 + x = ln5 + 7 - 3ln10

x(ln10 + 1) = ln5 + 7 -3ln10

x = (ln5 + 7 - 3ln10)/(ln10 + 1)

marlon
 
Ah, thank you very much. Your help is much appreciated. I could not fingure out how to get the x's out the correct way. I did not know this was allowed. Thank you again.
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top