Solve for r 1400 = 1000 [(1+r/12) ^60]

Will give medal.

I'm stuck at 7/5 = (12+r)^60 ... don't know how to simplify that

Question

Solve for r 1400 = 1000 [(1+r/12) ^60]

Will give medal.

I'm stuck at 7/5 = (12+r)^60 ... don't know how to simplify that

anonymous · Answer

answer is  ~  0.0675 ....6.75%    ...but I want to know how to simplify to get there.

paxpolaris · Answer

$$1400 = 1000\left( 1+\frac r {12} \right) ^{60}$$$$\frac75= \left( 1+\frac r {12} \right) ^{60}$$ ...next take the log of both sides

anonymous · Answer

can you show those steps

paxpolaris · Answer

$$\log \left( \frac75 \right)=60\times \log \left( 1+\frac r {12} \right)$$

paxpolaris · Answer

$${\log \left( 1.4 \right)\over 60}= \log \left( 1+\frac r {12} \right)$$

anonymous · Answer

okay, im following you. how do i get rid of the logs though?

anonymous · Answer

I need to get r by itself

paxpolaris · Answer

now reverse the log:
$$10^{\log(1.4)/60}=1+r/12$$

anonymous · Answer

that doesn't get the right answer

anonymous · Answer

oh wait it does!

anonymous · Answer

that becomes 10 to the power of 0.0024....and then multiply that by 12

anonymous · Answer

which there was an easier way of doing it then reversing the log

anonymous · Answer

wish*