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
Varvara68 [4.7K]
3 years ago
5

What are the solutions to the equation x2 − 1 = 399?

Mathematics
2 answers:
Mila [183]3 years ago
8 0

Answer:A

Step-by-step explanation:

mihalych1998 [28]3 years ago
3 0

Good evening ,

Answer :

A.

x = ±20

Step-by-step explanation:

x² − 1 = 399 ⇔ x²= 400 ⇌ x² = 20² ⇌ x² − 20² = 0 ⇌ (x-20)(x+20) = 0

⇌ x = 20 or x = -20.

:)

You might be interested in
8. Solve for y:<br> 24 = 3y
Gnom [1K]

Answer:

y=8

Step-by-step explanation:

24/3=8

3*8=24

hope this helps :3

if it did pls mark brainliest

4 0
3 years ago
A scuba diving company currently charges $100per dive. On average, there are 30 customers per day. The company performed a study
Semenov [28]

A. Total Revenue (R) is equal to price per dive (P) multiplied by number of customers (C). We can write R=PC.

Per price increase is $20. So four price increase is $20*4=$80. Hence, price per dive is 100+80=$180.

Also per price increase, 2 customers are reduced from 30. For 4 price increases, 4*2=8 customers are reduced. Hence, total customers is 30-8=22.

So Total Revenue is:

R=180*22=3960


B. Each price increase is 20. So x price increase is 20x. Hence, new price per dive would be equal to the sum of 100 and 20x.

Also per price increase, customers decrease by 2. So per x price increases, the customer decrease is 2x. Hence, new number of customers is the difference of 30 and 2x.

Therefor we can write the quadratic equation for total revenue as the new price times the new number of customers.

R=(100+2x)(30-2x)=-40x^{2}+400x+3000


C. We are looking for the point (x) at which the equation modeled in part (B) gives a maximum value of revenue (y). That x value is given as x=-\frac{b}{2a}, where a is the coefficient of x^{2} and b is the coefficient of x. So we have,

x=-\frac{b}{2a}=- \frac{400}{(2)(-40)}=5

That means, the greatest revenue is achieved after 5 price increases. Each price increase was 20, so 5 price increase would be 5*20=100. So the price that gives the greatest revenue is 100+100=200.

ANSWERS:

A. $3960

B. R=-40x^{2}+400x+3000

C. $200

4 0
3 years ago
7) First factor out the greatest common factor from each term. Then factor the remaining polynomial.
Stolb23 [73]

Answer: -138

Step-by-step explanation:

pls help me with this on my account

gaston is making a tent for boy scout camp. he has been instructed to use canvas on all of the sides except the bottom, which will be made out of a different material. how much canvas will gaston need?

6 0
3 years ago
Please help!! thank you.
Zina [86]

(A) Product of -2x^{3}+x-5 and x^{3}-3x-4 is:

(-2x^{3}+x-5)(x^{3}-3x-4)

=-2x^{3}(x^{3}-3x-4)+x(x^{3}-3x-4)-5(x^{3}-3x-4)

=(-2x^{3})(x^{3})+(-2x^{3})(-3x)+(-2x^{3})(-4)+x(x^{3})+(x)(-3x)+(x)(-4)+(-5)(x^{3})+(-5)(-3x)+(-5)(-4)

=-2x^{6}+6x^{4}+8x^{3}+x^{4}-3x^{2}-4x-5x^{3}+15x+20

=-2x^{6}+6x^{4}+x^{4}+ 8x^{3}-5x^{3}-3x^{2}-4x+15x+20

=-2x^{6}+7x^{4}+3x^{3}-3x^{2}+11x+20

(B) Yes.

Product of -2x^{3}+x-5 and x^{3}-3x-4 = Product of x^{3}-3x-4 and -2x^{3}+x-5 because multiplication is commutative.

Commutative Property of multiplication says that a.b = b.a.

Thus, multiplication is same irrespective of the order of two numbers.



5 0
3 years ago
What is the product?
sveticcg [70]

Answer:

third answer is correct

Step-by-step explanation:

hello,

we need to compute

5*(-1)+(-2)*(-1)=-5+2=-3

-6*(-1)+(2)*(-1)=6-2=4

so the correct answer is

   -3

    4

hope this helps

8 0
3 years ago
Other questions:
  • Sean has some candy bars that he wants to give away. he is going to give each person 1/8 of a bar, and he has 2 3/4 bars to give
    5·2 answers
  • Colby took out a sinlge payment loan for $550 that charged a $60 fee. How much does he have to pay by the time the loan reaches
    6·2 answers
  • Explain the difference between the average rate of change of y as x changes from a to b, and the instantaneous rate of change of
    12·1 answer
  • What is the best approximation of the equations that these two lines represent?
    14·1 answer
  • I don't inderstand how would i graph and find the range and domain
    11·1 answer
  • Help me plz show work​
    6·1 answer
  • Can u help me awser this
    15·2 answers
  • Employee working at Electronics store and $4560 for working eight months during the summer at the three month mark how much did
    5·1 answer
  • ⁵
    14·1 answer
  • Calculate the distance between (2, -2) and (-3, -1).
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!