Math  /  Algebra

QuestionSolve the following exponential equation. Express your answer as both an exact expression and a decimal approximation rounded to two decimal places. 3e3x+4=653 e^{3 x+4}=65

Studdy Solution

STEP 1

What is this asking? We need to find the value of xx that makes 3e3x+43e^{3x+4} equal to 65, and give the answer in exact form and as a decimal. Watch out! Remember those exponent rules and be careful with the order of operations when solving for xx!

STEP 2

1. Isolate the exponential term
2. Apply the natural logarithm
3. Solve for xx
4. Calculate the approximate value

STEP 3

We want to get e3x+4e^{3x+4} by itself.
To do this, we **divide both sides** of the equation by **3**: 3e3x+43=653 \frac{3e^{3x+4}}{3} = \frac{65}{3} e3x+4=653 e^{3x+4} = \frac{65}{3} Now we have the exponential term isolated!

STEP 4

To get 3x+43x+4 out of the exponent, we can **apply the natural logarithm** to both sides of the equation: ln(e3x+4)=ln(653) \ln(e^{3x+4}) = \ln\left(\frac{65}{3}\right) Remember, the natural logarithm and the exponential function with base ee are inverse operations, so they "undo" each other!

STEP 5

Using the property ln(ea)=a\ln(e^a) = a, we can simplify the left side: 3x+4=ln(653) 3x+4 = \ln\left(\frac{65}{3}\right)

STEP 6

Let's **isolate** the term with xx by **subtracting 4** from both sides: 3x+44=ln(653)4 3x + 4 - 4 = \ln\left(\frac{65}{3}\right) - 4 3x=ln(653)4 3x = \ln\left(\frac{65}{3}\right) - 4

STEP 7

Finally, we **divide both sides by 3** to solve for xx: 3x3=ln(653)43 \frac{3x}{3} = \frac{\ln\left(\frac{65}{3}\right) - 4}{3} x=ln(653)43 x = \frac{\ln\left(\frac{65}{3}\right) - 4}{3} This is our **exact solution**!

STEP 8

Now, we can use a calculator to find the approximate value of xx: x3.05443 x \approx \frac{3.054 - 4}{3} x0.9463 x \approx \frac{-0.946}{3} x0.315 x \approx -0.315 So, xx is approximately equal to **-0.32** when rounded to two decimal places.

STEP 9

The exact solution is x=ln(653)43x = \frac{\ln\left(\frac{65}{3}\right) - 4}{3} and the approximate solution is x0.32x \approx -0.32.

Was this helpful?

Studdy solves anything!

banner

Start learning now

Download Studdy AI Tutor now. Learn with ease and get all help you need to be successful at school.

ParentsInfluencer programContactPolicyTerms
TwitterInstagramFacebookTikTokDiscord