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
EleoNora [17]
2 years ago
13

Factorise and solve x^2 + 4x -21 = 0

Mathematics
2 answers:
Korvikt [17]2 years ago
3 0

Answer:

(x + 7) (x - 3)

Step-by-step explanation:

Find 2 numbers that add to 4 and multiply to -21

(x + 7) (x - 3)

Ahat [919]2 years ago
3 0

Answer:

(x+7)(x-4) x=-7,4

Step-by-step explanation:

The factors of -21 that add up to 4 are 7 and -3, so put those as your two second values in your binomials and solve for x, in this case being the negative versions of the second term in the binomial

You might be interested in
Damaged items are marked down 25% to 40%. A newspaper coupon holder; to an additional 10% markdown of the new price due to the d
kobusy [5.1K]

Answer:

B. GHC 50.00

Step-by-step explanation:

The given parameters are;

The percentage by which damaged items are marked down = 25% to 40%

The percentage markdown offered by the newspaper coupon = 10%

The original marked price of the item = GHC 100

We note that a markdown is the difference between the price an item is placed at for retail sale, and the actual price the item is sold

Given that the item is damaged, to have the lowest price, we apply the largest markdown of 40% as follows;

Price of item marked down due to damage, we remove 40% from the price to get;

The markdown due to damage = 40/100 × GHC 100 = GHC 40

The markdown the coupon holder is to get = 10% of the retail price

Given that the damage is not mentioned in the newspaper, we have;

∴ The markdown the coupon holder is to get = 10/100 × GHC 100 = GHC 10

The total markdown is therefore equal to GHC 40 + GHC 10 = GHC 50

Therefore;

The lowest price of the item = Original price - Maximum markdown

The lowest price of the item = GHC 100 - GHC 50 = GHC 50

Learn more about markdown here;

brainly.com/question/20705786

5 0
3 years ago
Which expressions are equivalent to 2(25)?
g100num [7]

Answer:

2(20+5)

2(10+15)

Step-by-step explanation:

When you add 20+5 together you get 25 which is the same to 2(25)

When you add 10+15 together you get 25 which is the same to 2(25)

6 0
3 years ago
Read 2 more answers
For his long distance phone service, Juan pays a $5 monthly fee plus 9 cents per minute. Last month, Juan's long distance bill w
Lera25 [3.4K]

Answer:

80 or 81 minutes

Step-by-step explanation:

12.28-5 =7.28 7.28/.09= 80.88

4 0
3 years ago
A researcher was interested in utilities provided by city governments. The researcher randomly selected 20 counties from a list
DaniilM [7]

Answer:

1. The population of interest is all city goverments in the U.S.

5. The parameter of interest is the proportion of the city goverments in the U.S. that provide electricity to their residents.

Step-by-step explanation:

Hello!

Missing questions:

Which of the following is true? Select all that apply.

  1. The population of interest is all city governments in the U.S.
  2. The population of interest is the 192 cities.
  3. The population of interest is all city governments that provide utilities to their residents.
  4. The population of interest is 6.25%
  5. The parameter of interest is the proportion of the city governments in the U.S. that provide electricity to their residents.
  6. The parameter of interest is 6.25%
  7. The population of interest is the 20 counties.
  8. The parameter of interest is the list of all counties in the U.S.

The objective of this essay is to test utilities provided by city governments, for this a sample of 20 counties was taken then contacted each city of them counting how many of them provided utilities to their residents, finding out that 12 out of 192 cities (6.25%) provided electricity to their residents.

The study variable is:

X: Number of city governments that provide utilities (electricity) to their residents, in a sample of 192.

The population of the study is the city governments in the U.S.

And the parameter of interest is the population proportion of city governments in the U.S. that provide electricity to their residents.

I hope it helps!

4 0
3 years ago
Tom puts a cup of tea in his microwave oven He knows that the final temperature of the water will be a function of the number of
bearhunter [10]
B and C are both correct 

t(s) is equivalent to the temperature of the tea after s amount of seconds
4 0
3 years ago
Other questions:
  • How do you factor 20x^2 - 66x +54 ?
    7·1 answer
  • help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! plzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz! can anyone answer all of the unanswered questions in the
    14·2 answers
  • C (5,4) and D (3,10) find the length
    6·2 answers
  • Please help on this...
    13·1 answer
  • Bottom#9 Find the value of X. Round answer to nearest tenth please.
    10·1 answer
  • What is the measure of angle d
    11·1 answer
  • A bag weighs 336 ounces when full and 171 ounces when half full. what does the bag weigh when empty?
    9·2 answers
  • Milligrams would you administer?
    10·1 answer
  • The product of a number and -3 increased by 4 is 12
    13·1 answer
  • QUESTION ON PIC THXXXXX !!! Question
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!