All categories

3 years ago

A student solved log4(2x – 12) = 3, as shown.

2 answers:

4 0

1-When you have a the logarithm given in the problem above, you can solve it by using the correct properties for logaritms.
2- The students could solve it as below:
log4(2x-12)=3
4^[ log4(2x-12)]=4^3
3- By definition a^log(x)=x, therefore,
2x-12=4^3
2x-12=64
4- Now, the students can solve for x:
x=38
The first step is incorrect, because the term on the right member must be 4^3.

irinina [24]3 years ago

3 0

Answer:

The correct answer is x = 38.

Step-by-step explanation:

The error is in Step 1. They translated from logarithmic to exponential form incorrectly.

The student should have used 4 as the base and 3 as the exponent. This would result in 64, not 81, on the right side of the equation.

You might be interested in

What is the best approximation of the length of segment QS? (Note: cos 80° = 0.17)

matrenka [14]

Answer: $QS=11.8cm$

Step-by-step explanation:

1. You have the following information:

- The lenght of $RS$ is 2 centimeters.

- The angle m∠S=80°.

- Cos80°=0.17

2. Therefore, you can calculate the lenght of the segment $QS$ as following:

$cos80=\frac{adjacent}{hypotenuse}$

$adjacent=2cm\\hypotenuse=QS\\cos80=0.17$

3. Substitute values and solve for $QS$ :

$0.17=\frac{2cm}{QS}\\QS=\frac{2cm}{0.17} \\QS=11.76cm$

4. To the nearest tenth:

$QS=11.8cm$

6 0

3 years ago

The living room in a new house has the dimensions shown. What is the volume of the room?

irga5000 [103]

Answer:

v = 220 yd²

Step-by-step explanation:

Small portion

v = 5 * 4 * 3

v = 60 yd²

Large portion

v = 9 * 6 * 3

v = 162 yd²

Total

v = 60 + 162

v = 220 yd²

5 0

3 years ago

Carol had 2 pieces of paper. She gave each student in her class 1/4 of a piece of paper. If Carol gave away all her pieces of pa

NeX [460]

She gave her paper away to eight people because giving her paper pieces to four students ,equals one whole piece of paper, and she has two, so two times 4 equals 8.
Answer:8

4 0

3 years ago

Read 2 more answers

Find the value of x in the following parallelogram: 2x - 10 2x + 50

Lerok [7]

Answer:

-40

Step-by-step explanation:

7 0

3 years ago

Suppose that J and K are points on the number line. If JK=12 lies at 3 , where could K be located? If there are several location

zmey [24]

Answer:

15, -9

Step-by-step explanation:

It is given that J and K are points on the number line. J lies at 3 and JK=12.

We kneed to find the location of K.

A number line is a straight line with numbers placed at equal intervals and extended infinitely in any direction.

If K lies on the left side of J then the location of K is

3 + 12 = 15

If K lies on the right side of J then the location of K is

3 - 12 = -9

The locations of K are defined by the below number.

Therefore the locations of K are 15 and -9.

8 0

3 years ago