Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 decade ago

Solve the equation: 1.2e^(-5x)+2.6=3?

I am about to flunk Algebra Two and I really need help. This is one of the problems. If you could help me I would be really happy.Thank You.

The equation is: 1.2e^(-5x)+2.6=3

This chapter is about Expoential and Logarithmic equations.

Update:

I forgot to say I need to know detailed steps to solve it, just not the answer please!

Update 2:

I need the steps in words. I dont know what you did with just numbers. but thanks so far tho!

6 Answers

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  • 1 decade ago
    Best Answer

    1.2e^(-5x)+2.6=3

    1.2e^(-5x) = .4

    e^(-5x) = .4/1.2 = 1/3

    1/[e^(5x)] = 1/3

    e^(5x) = 1/3

    5x = ln(1/3)

    x = [ln(1/3)]/5

  • 3 years ago

    technique A: 5X = a hundred and fifty five 5 x X = a hundred and fifty five X = a hundred and fifty five/5 X = 31 OR technique B: 5X = a hundred and fifty five 5 x X = a hundred and fifty five 5 = a hundred and fifty five/X X = a hundred and fifty five/5 X = 31 the suggestions-blowing technique is way less complicated, however the backside is likewise in theory suggestions-blowing. In tests, the suggestions-blowing technique is the appropriate to apply. desire this enables!

  • 1 decade ago

    I'm assuming you may want the solution panned out into a more complicated form?

    First you should isolate your operator.

    Subtract 2.6 from both sides.

    Divide both sides by 1.2

    Then take ln of both sides

    Now you have -5x=ln1/3

    Dvide both sides by -5.

    You'll have to use a calculator for parts of this problem...

    the resulting solution is a decimal.. 0.219722..

    Divide by -5 to isolate your variable.

  • 1 decade ago

    1. subtract 2.6 from both sides

    1.2e^(-5x) = .4

    2. divide both sides by 1.2

    e^(-5x) = (1/3)

    3. to clear the e take the ln of both sides

    ln (e^(-5x)) = ln(1/3)

    -5x= ln(1/3) or -5x = - ln(3)

    answer x=(1/5)ln(3)

    I used the following laws:

    ln (e^(a))=a

    ln(1/a) = ln(a^(-1)) = -ln(a)

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  • 1 decade ago

    1.2e^ (-5x) = 0.4

    0.4 ^ (-15x) = 0.4

    x = - 1/ 15

  • 1 decade ago

    its called a calculator :-P - grade 10 math doesnt cover this yet :P

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