Posted by **Ku** on Sunday, June 23, 2013 at 1:44am.

Solve the exponential equation algebraically

5^(-t/2) = 0.20

- Precal -
**MathMate**, Sunday, June 23, 2013 at 5:30am
5^(-t/2)=0.20

take log on both sides,

(-t/2)log(5)=log(0.20)

solve for t

-t/2 = log(0.20)/log(5)

t=-2log(0.20)/log(5)...isolate t

=log(1/0.04)/log(5)...absorb -2 into log(0.2)

=log(25)/log(5)... evaluate reciprocal

=2... laws of logarithm, 25=5²

## Answer this Question

## Related Questions

- College Algebra - Solve the exponential equation algebraically: 2^x+1=5^2x
- exponential equation-Algebra - Solve the exponential equation. Express the ...
- Math - Exponential equation - Solve the exponential equation. Express your ...
- pre-calculus 11 - I am asked to solve the absolute value equation of |1/2x +1...
- pre-calculus 11 - I am asked to solve the absolute value equation of |1/2x +1...
- Algebra Help - Let x = log_2 1/8 Write the exponential form of the equation and ...
- Precal - Prove algebraically that |w+z|<=|w|+|z| for any complex numbers w ...
- Algebra-please check my answers - Solve the equation by expressing each side as ...
- calculus - Please help me solve this equation. log[2](3)+log[2](x)=log[2](5)+log...
- calculus - Please help me? ln(x+1)-ln(x-2)=ln(5) 1. Solve equation by setting up...

More Related Questions