How do you solve 2^(x+1)=5^(1-2x)?

1 Answer
Feb 5, 2015

The answer is: x=(ln5-ln2)/(ln2+2ln5).

The only way to find the solutions of this equation is to pass both members as arguments of the logarithmics function, better in base e.

So:

2^(x+1)=5^(1-2x)rArrln2^(x+1)=ln5^(1-2x)rArr

(x+1)ln2=(1-2x)ln5rArrxln2+ln2=ln5-2xln5rArr

xln2+2xln5=ln5-ln2rArrx(ln2+2ln5)=ln5-ln2rArr

x=(ln5-ln2)/(ln2+2ln5).