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
Tom [10]
3 years ago
15

Solving Exponential Equations (lacking a common base) 4^x-5=8

Mathematics
2 answers:
avanturin [10]3 years ago
8 0

Answer:

x= 6 1/2 or 6.5

Step-by-step explanation:

4^x-5 =8

2^2(x-5) =2^3

since the base is equal, the powers are equal

2(x-5) = 3

2x - 10 = 3

2x = 3 + 10

2x = 13

2x/2 = 13/2

x = 6 1/2 or 6.5

Tju [1.3M]3 years ago
6 0

Answer:

6.5

Step-by-step explanation:

4^(x-5) = 8

2^[2(x-5)] = 2³

Equating powers:

2(x-5) = 3

x-5 = 3/2

x = 13/2 or 6½

You might be interested in
How many numbers less than 904 are divisible by 3
MaRussiya [10]

Answer:

301 is correct answer. Please Mark it as brainlist answer.

5 0
2 years ago
The formula can be used to work outthe cost, in riyals, of hiring a helmet inQatar for a number of days.Kasun wants to hire a bi
Margaret [11]

Answer:

The answer is below

Step-by-step explanation:

a) Cost of hiring the bicycle for 14 days is:

Cost = 65 * 14 days + 44 = 954 riyals

b) The number of days the bicycle is hired is to be the same as the number of days the bicycle is to be hired. Let us assume that the bicycle and helmet is to be hired for x days, hence:

Cost of bicycle = 65 * x + 14 = 65x + 44

Cost of helmet = 12.5 * x = 12.5x

Total cost = 65x + 44 + 12.5x = 77.5x + 44

Since 750 riyals is available, hence:

750 = 77.5x + 44

77.5x = 706

x = 9.11

Therefore the maximum number of days is 11. The total cost for 11 days is:

Total cost = 77.5(9) + 44 = 741.5 riyals

Money not spent = 750 riyals - 741.5 riyals = 8.5 riyals

6 0
3 years ago
A doctor released the results of clinical trials for a vaccine to prevent a particular disease. In these clinical​ trials, 200,0
CaHeK987 [17]

Answer:

1) No, there is  not  enough evidence to support the claim that the vaccine was effective (P-value=0.104) .

The null and alternative hypothesis are:

H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2< 0

being the subindex 1 for the experimental group and subindex 2 for the control group.

2) Test statistic z=-1.26

Step-by-step explanation:

This is a hypothesis test for the difference between proportions.

The claim is that the vaccine was effective.

Then, the null and alternative hypothesis are:

H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2< 0

The significance level is 0.01.

The sample 1 (experimental group), of size n1=100000 has a proportion of p1=0.0002.

p_1=X_1/n_1=21/100000=0.0002

The sample 2 (control group), of size n2=100000 has a proportion of p2=0.0003.

p_2=X_2/n_2=30/100000=0.0003

The difference between proportions is (p1-p2)=-0.0001.

p_d=p_1-p_2=0.0002-0.0003=-0.0001

The pooled proportion, needed to calculate the standard error, is:

p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{21+30}{100000+100000}=\dfrac{51}{200000}=0.00026

The estimated standard error of the difference between means is computed using the formula:

s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.00026*0.99974}{100000}+\dfrac{0.00026*0.99974}{100000}}\\\\\\s_{p1-p2}=\sqrt{0+0.0000000025}=\sqrt{0.0000000051}=0.000071

Then, we can calculate the z-statistic as:

z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{-0.00009-0}{0.000071}=\dfrac{-0.00009}{0.000071}=-1.26

This test is a left-tailed test, so the P-value for this test is calculated as (using a z-table):

P-value=P(z

As the P-value (0.104) is bigger than the significance level (0.01), the effect is not significant.

The null hypothesis failed to be rejected.

There is  not  enough evidence to support the claim that the vaccine was effective.

6 0
3 years ago
Problem 1: 2x &gt; 4x - 6<br> problem 2: -3r &lt; 10 - r<br> problem 3: 5c - 4 &gt; 8c + 2
Trava [24]
<span>Problem 1: 2x > 4x - 6
                  2x < 6  
                    x < 3

problem 2: -3r < 10 - r
                   -2r < 10
                      r > -5

problem 3: 5c - 4 > 8c + 2
                       3c < -6
                         c < -2</span>
8 0
3 years ago
A farm produce an average of 17.1 liters of milk per day . About how many days will it take to produces 200 liters of milk
Dafna11 [192]
Amounttotal=amount per day times number of days
200=17.1 times d
divide both sides by 17.1
11.695=d
about 12 days
7 0
3 years ago
Other questions:
  • 2^3 times ... times 2/3
    7·1 answer
  • 54 is 36% of what number?
    8·1 answer
  • What is the surface area of this right circular cone?
    10·1 answer
  • HELP!!!!!!
    12·1 answer
  • Describe the nature of the roots for this equation.
    11·1 answer
  • #3 - Simplify the expression. Type your answer with all lowercase letters and no spaces. Type your p variable first and g variab
    6·1 answer
  • Which number completes the table...?<br> 24<br> 54<br> 84<br> 114<br> 14<br> 19
    11·1 answer
  • PLEASE HELP ME!!!!
    7·1 answer
  • 3×-5=16 and 3×=21
    9·2 answers
  • Which Of The Following is Graphed Below
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!