1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
NemiM [27]
3 years ago
10

Please show ALL work! Solve for x: log₂x+log₂(x-6)=4

Mathematics
1 answer:
Vlad [161]3 years ago
5 0
Answer: x = 8

---------------------------------------------
---------------------------------------------

I'm going to use the notation log(2,x) to indicate "log base 2 of x". The first number is the base while the second is the expression inside the log (aka the argument of the log)

log(2,x) + log(2,(x-6)) = 4
log(2,x*(x-6)) = 4
x*(x-6) = 2^4
x*(x-6) = 16
x^2-6x = 16
x^2-6x-16 = 0
(x-8)(x+2) = 0
x-8 = 0 or x+2 = 0
x = 8 or x = -2

Recall that the domain of log(x) is x > 0. So x = -2 is not allowed. The same applies to log(2,x) as well.

Only x = 8 is a proper solution.

------------------------

You can use the change of base rule to check your work
log base 2 of x = log(2,x) = log(x)/log(2)
log(2,(x-6)) = log(x-6)/log(2)

So,
(log(x)/log(2)) + (log(x-6)/log(2)) = 4
(log(8)/log(2)) + (log(8-6)/log(2)) = 4
(log(8)/log(2)) + (log(2)/log(2)) = 4
(log(2^3)/log(2)) + (log(2)/log(2)) = 4
(3*log(2)/log(2)) + (log(2)/log(2)) = 4
3+1 = 4
4 = 4
The answer is confirmed

You might be interested in
How do i do this question
oksano4ka [1.4K]

Answer:

A) 4.18

B)7.65

Step-by-step explanation:

You have to use a calculator

7 0
2 years ago
A) What is the slope and the y-intercept of the equation?
Zielflug [23.3K]

Answer:

see explanation

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + b ( m is the slope and b the y- intercept )

Calculate m using the slope formula

m = \frac{y_{2}-y_{1}  }{x_{2}-x_{1}  }

with (x₁, y₁ ) = (0, 3) and (x₂, y₂ ) = (4, 0) ← 2 points on the line

m = \frac{0-3}{4-0} = \frac{-3}{4} = - \frac{3}{4}

The y- intercept is where the line crosses the y- axis

The line crosses the y- axis at (0, 3 ) ⇒ b = 3

(b)

y = - \frac{3}{4} x + 3 ← equation of line

8 0
3 years ago
Based on its number of terms, what is the<br><br> polynomial 2p2 – 2p called?<br><br><br> PLS HELP
fenix001 [56]

Answer: quadratic

Step-by-step explanation:

3 0
3 years ago
How far from the base of the house do you need to place a 15’ ladder so that it exactly reaches the top of a 12’ wall?
FromTheMoon [43]

Answer:

3' away

Step-by-step explanation:

8 0
3 years ago
Read 2 more answers
2+2= what plz I need help
jekas [21]

Answer:4

Step-by-step explanation:

7 0
3 years ago
Read 2 more answers
Other questions:
  • Mrs. Kuss is playing a crazy game of Monopoly with her son Ethan. In order to land on Boardwalk she will need double sixes. What
    13·2 answers
  • You have to pick 5 members of the student council to go to meeting. If there are 10 members total, how many 5 member teams can y
    13·1 answer
  • Whats 48.7 divided by 1.2
    10·2 answers
  • Which radical expressions are equivalent to the exponential expression below ? Check all that apply . (13 + 8) ^ (1/2) A. (13 +
    9·1 answer
  • If 5 cans of baked beans cost $2.85, how<br> many cans of baked beans can be bought<br> for $19.38?
    10·1 answer
  • Find the midpoint between (-1+9i) and B=(5-3i)
    9·2 answers
  • What is the answer to 3x – 3 = 18​
    13·2 answers
  • You have a $20 coffee card. Each time you go there, you spend $1.25. The equation y = -1.25 x + 20 represents how much you have
    12·2 answers
  • I'm not sure what trig function to use. Someone please help, and please answer sedulously, and not just for points. Thank you in
    7·1 answer
  • What is 8 and 4/25 and as a mixed fraction or mixed number.
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!