(03/01) ALG 2 Unit 5B: Solving Log Equations

(03/01) ALG 2 Unit 5B: Solving Log Equations

Multiple Choice

Solve for x. 

 $3^{\left(n-7\right)}-3=24$  

• 3

• 8

• 10

• No solution

Today, will we focus on the opposite of exponential :

Solving Log Equations using the same steps as solving exponential!!

Solve:

 $\log_3\left(x-12\right)=2$  

• Since the log function is isloated, we can skip step 1 (THERE IS NO K!)

• Step 2: Rewrite as an exponential function

•  $3^2=x+12$  

• Step 3: Solve for x. 

•  $3^2-12=x$  

•  $x=-3$  

Solve:

 $\log_3x-7=-2\ \ \rightarrow\log_3\left(x\right)-7=-2$  

• Step 1: Isolate the log function by adding 7 to both sides!

•  $\log_3x-7+7=-2+7$  

•  $\log_3x=5$  

• Step 2: Rewrite as an exponential function. 

•  $3^5=x$  

• Step 3: Solve for x

•  $x=243$  

Solve:

 $\ln\left(x+15\right)+27=31$  

• Step 1: Isolated the natural log (ln) by subtracting 27 from both sides. 

•  $\ln\left(x+15\right)+27-27=31-27$  

•  $\ln\left(x+15\right)=4$  

• Step 2: Rewrite as a natural exponential function!  $\ln\rightarrow e$  

•  $e^4=x+15$  

• Solve for x by subtracting 15 on both sides  $e^4-15=x+15-15$  

•  $x\approx39.60$  

Multiple Choice

log₈(4x+4)=2

• 15

• 12

• 10

• 3

Multiple Choice

log₂(x + 5) = 3

• 3

• 4

• 5

• 6

Multiple Choice

Solve for x.
 $\log_8\left(x+4\right)=2$  

• 12

• 60

• 64

• No solution

What's Next??

• DO NOT Log off of zoom until you are dismissed!!

• You will have a graded assignment on inverse & solving exponential & log functions TOMORROW during Digital Learning DAY!! It is DUE by 2 pm!! No exceptions!!

• PLEASE continue to complete makeup work!! Ms. Thames will start back sending out codes when she returns tomorrow!!

• Complete the google form for missing work!!

Today Assignment!!

• Go back to joinmyquiz.com & enter the code for your class period ONLY!!

• 1st Period: 32897660

  
  

• 4th Period: 09960060

• This is DUE at the end of class!!