Wednesday

January 28, 2015

January 28, 2015

Posted by **tina** on Friday, November 11, 2011 at 12:40pm.

18e^-x -e^x=7

- precalculus -
**Reiny**, Friday, November 11, 2011 at 12:47pm18/e^x - e^x = 7

let e^x = a

18/a - a - 7 = 0

18 - a^2 - 7a = 0

a^2 + 7a - 18 = 0

(a+9)(a-2) = 0

a = -9 or a = 2

then

e^x = -9 ----> no solution

or

e^x = 2

x = ln 2

**Answer this Question**

**Related Questions**

Math - Solve the logarithmic equation. Express your solutions in exact form only...

College Algebra - Solve the logarithmic equation. Express your solutions in ...

precalculus - solve the logarithmic equation . express solution in exact form ...

precalculus - solve logarithmic equation in exact form only. show work. log_5(x-...

precalculus - solve the exponential equation express in exact form only show all...

pre calculus - Solve the exponential equation Express you solutions in exact ...

college algebra - Solve the exponential equation. Express your solutions in ...

Math - 2 - Solve the exponential equation. Express your solutions in exact form ...

precalculus - solve exponential equation. express in exact form. e^x-42e^-x= -19

Math - Exponential equation - Solve the exponential equation. Express your ...