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3 years ago

Use the quadratic formula to solve the equation X^2+9X+20=0

Mathematics

2 answers:

lions [1.4K]3 years ago

6 0

Answer:

x=-4

x=-5

Step-by-step explanation:

Stells [14]3 years ago

3 0

Answer:

-4 or -5

Step-by-step explanation:

Well, you have to first understand variables a, b, and c. A in this equation is 1, b is 9, and c is 20. Then you plug those into -b ± sqrt (b^2-4ac)/2a and find that the discriminant, or what is under the square root, is one. Your two roots will be -4 and -5.

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An experiment consists of ranomly drawing three cards in succession without replacement from a standard deck of 52 cards. Let A

nadya68 [22]

Answer:

0.0045248 ;

0.1312218 ;

0.0001809 ;

0.1659729

Step-by-step explanation:

Number of Kings in deck = 4

Total number of cards in deck = 52

Picking without replacement :

A = King on first draw :

P(A) = 4 / 52

A = King on 2nd draw :

P(B) = 3 / 51

A = King on 3rd draw :

P(C) = 2 / 50

1.) P(A n B) = P(A) * P(B)

P(A n B) = 4/52 * 3/51 = 12 / 2652 = 0.0045248

2.) P(A u B) = P(A) + P(B) - P(AnB)

P(AuB) = 4/52 + 3/51 - 0.0045248 = 0.1312218

3.) P(A ∩ B ∩ C) = P(A) * P(B) * P(C)

P(A ∩ B ∩ C) = 4/52 * 3/51 * 2/50 = 0.0001809

4.) P(A U B U C) =

P(A) + P(B) + P(C) - P(AnB) - P(AnC) - P(BnC) - P(AnBnC)

P(AnC) = P(A) * P(C) = 4/52 * 2/50 = 0.0030769

P(BnC) = P(B) * P(C) = 3/51 * 2/50 = 0.0023529

4/52 + 3/51 + 2/50 - 0.0045248 - 0.0030769 - 0.0023529 + 0.0001809 = 0.1659729

6 0

3 years ago

The heights of two cylinders are in the ratio 3:1 if the volumes of two are same find the ratio of their respective radii

Soloha48 [4]

Answer:

$\sqrt{3}$ :1

Step-by-step explanation:

Ratio of height of two cylinders are 3:1

Let C2 has the height x

then height of C1 is 3x

Let r1 is the radius of C1

and r2 is the radius of C2

As given that volume of both are equal

Also we know that formula for the volume of the cylinder is

V= π r²h

for C1

V= π (r1)²h

for C2

V=π (r2)²h

As volume of both are same so equating them

π (r1)²h1 = π (r2)²h2

as h1 =3x and h2=x

putting values

π (r1)²(3x) = π (r2)²(x)

cancelling out π and x from both side of the equation

3(r1)²= (r2)²

Taking square root of both sides give

$\sqrt{3(r1)^{2} }=\sqrt{(r2)^{2} }$

r1 ( $\sqrt{3}$ ) = r2

r1 : r2 = $\sqrt{3}$ :1

7 0

4 years ago

g People between the ages of 65 and 70 were studied to see if those who exercise more were healthier. One measure of health was

liubo4ka [24]

Answer:

If the person selected had high blood pressure, the probability that he or she did not exercise is P=0.643.

Step-by-step explanation:

We have a group of people between agss of 65 and 70.

They are divided in two groups regarding their amount of exercise: "none", "moderate" and "high".

The response variable is blood pressure, that was categorized as "normal"or "high".

Then, we have the frequencies table as:

Amount of exercise None Moderate High

Blood pressure High 54 23 7

Blood pressure Normal 86 76 32

We have to calculate the probability that, given that the person had high blood pressure, he or she did not exercise.

If the person had high blood pressure, it can be of the any of the 3 groups of exercise amount. There are 54 people with high blood pressure that did not exercise, 23 that did moderate amount of exercise, and 7 that did a high amount.

Then, the probability can be calculated dividing the amount of people that had high blood pressure and did not exercise, by all the people that have high blood pressure (regarding the amount of exercise):

$P(N | HP)=\dfrac{54}{54+23+7}=\dfrac{54}{84}=0.643$

If the person selected had high blood pressure, the probability that he or she did not exercise is P=0.643.

5 0

3 years ago

Which of the following is x=-5 a solution ?

Katarina [22]

Answer:

C and D

Step-by-step explanation:

Plug X in and see which equations/expressions are true

8 0

3 years ago

Read 2 more answers

Given that weekly demand curve of a local wine producer is p = 50 − 0.1q, and that

rusak2 [61]

Answer:

Z(p) = -10p² + 600p - 6500

Step-by-step explanation:

Demand curve p = 50 - 0.1 q

Total cost function C(q) = 1500 + 10q

where q is the number of bottles produced each day and p is the selling prices per bottle.

Now, p = 50 - 0.1 q

o.1 q = 50 - p

q = 500 - 10p

Revenue = price × quantity = p × q

= p ( 500 - 10p)

= 500 p - 10p²

Profit = total revenue - total cost

Let Profit be Z since profit is function of price, therefore

Z(p) = pq - C(q)

Z (p)= 500 p - 10p² - (1500 + 10q)

Substituting the value of q in above expression,

Z(p) = 500 p - 10p² - ( 1500 + 10 (500 - 10p))

Z(p) = 500p -10p² - 1500 -5000 + 100p

Z(p) = -10p² + 600p - 6500

So, the weekly profit as a function of price p is Z(p) = -10p² + 600p - 6500.

3 0

4 years ago