What are the roots of this equation x^2-4x+9=0?

Answer:

136+(4n-8)=180

136+4n-8=180

4n+128=180

4n=52

n=13

Step-by-step explanation:

please mark me as brainliest

Answer:

x ≈ 13.7

Step-by-step explanation:

Using the cosine ratio in the right triangle

cos70° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{x}{40}[/tex] ( multiply both sides by 40 )

40 × cos70° = x , then

x ≈ 13.7 ( to the nearest tenth )

Answer:

Step-by-step explanation:

Rolling two dice, there are 6*6 = 36 outcomes

The outcomes with the difference of 4:

Required probability:

Correct choice is b

Answer:

x = 1, y = −1

x = 5/2, y = 1/2

Step-by-step explanation:

From the question given above, the following data were obtained:

y = 2x² − 6x + 3 ........ (1)

y = x − 2 ...... (2)

We can obtain the solutions to the equation as follow:

y = 2x² − 6x + 3 ........ (1)

y = x − 2 ...... (2)

Substitute the value of y in equation 2 into equation 1

y = 2x² − 6x + 3

y = x − 2

2x² − 6x + 3 = x − 2

Rearrange

2x² − 6x − x + 3 + 2 = 0

2x² − 7x + 5 = 0

Solve by factorization

Obtain the product of 2x² and 5. The result is 10x².

Find two factors of 10x² such that their sum will result to −7x.

The factors are −2x and −5x.

Replace −7x in the equation above with −2x and −5x as shown below:

2x² − 2x − 5x + 5 = 0

2x(x − 1) − 5(x − 1) = 0

(x − 1)(2x − 5) = 0

x − 1 = 0 or 2x − 5 = 0

x = 1 or 2x = 5

x = 1 or x = 5/2

Substitute the value of x into equation 2 to obtain y

y = x − 2

x = 1

y = 1 − 2

y = −1

x = 5/2

y = x − 2

y = 5/2 − 2

y = (5 − 4)/2

y = 1/2

SUMMARY:

x = 1, y = −1

x = 5/2, y = 1/2

Answer:

A

Step-by-step explanation:

Divide both sides with -16. ALWAYS remember that if you divide any number with a negative number, this "< ≤ > ≥" symbols have to change to the opposite direction

Given:

The mass function is:

[tex]m(v)=4.5v[/tex]

where v is the volume in cubic centimeters.

The force function is:

[tex]F(m)=800m[/tex]

To find:

The composite function can be used to find the force of the object based on its volume.

Solution:

The composite function can be used to find the force of the object based on its volume is:

[tex]F(m(v))=F(4.5v)[/tex]              [tex][\because m(v)=4.5v][/tex]

[tex]F(m(v))=800(4.5v)[/tex]              [tex][\because F(m)=800m][/tex]

[tex]F(m(v))=3600v[/tex]

Therefore, the correct option is D.

Answer: F(m(v)) = 3,600v

Step-by-step explanation:DDDD

Answer:

Step-by-step explanation:

P = 2(L + W)

Area = L*W

Area = 192

(L + W)*2 = 56

L+W = 28

L = 28 - W

W*(28 - W) = 192

28W - w^2 = 92

-w^2 + 28w - 192 = 0

w^2 - 28w + 192  = 0

This factors into

(w - 12)(w - 16) = 0

w - 12 = 0

w = 12

L = 28 - 12 = 16

Answer:

a.is approximately normal because of the central limit theorem.

Step-by-step explanation:

The central limit theorem states that if we have a population with mean μ and standard deviation σ and we take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed.

For any distribution if the number of samples n ≥ 30, the sample distribution will be approximately normal.

Since in our question, the sample of observations is 50, n = 50.

Since 50 > 30, then our sample distribution will be approximately normal because of the central limit theorem.

So, a is the answer.

Answer:

hundreths the 9 represents 900

Step-by-step explanation:

Answer:

900

Step-by-step explanation:

1,905

Expand the number

1000 + 900 + 5

900 is the value of the 9

Answer:

-10

Step-by-step explanation:

5(2) or fives times two is positive ten. The rule about multiplying with negatives is a negative times a positive is a negative. We take the multiplication answer from 5(2)=10 and apple the nagative from 5(-2). Hope this helps:)

Answer:

72?

Step-by-step explanation:

V=whl=4 x 2 x9=72

Answer:

2 solutions

Step-by-step explanat

ion:|2x-3|-|3x-2|=0

<=>|2x-3|=|3x-2|

<=>2x-3=3x-2

Or 2x-3=-3x+2

<=>2x-3x=-2+3

or 2x+3x=2+3

<=>x=-1

Or x=1

Answer:

H. 40 inches

Step-by-step explanation:

On Wednesday, he is 40 inches taller. ... That would make 5 days of growth, for 100 inches. But this is only 3 days therefore he would grow 40 inches taller

Answer:

2.5L of 10% salt solution and 7.5L of the 30% salt solution

Step-by-step explanation:

let the amount of L in the 10% solution be 'x'

let the amount of L in the 30% solution be '10-x'

* because they add up to a total of 10L

10%(x) + 30%(10-x) = 25%(10)

0.1x + 3 - 0.3x = 2.5

-0.2x = -0.5

x = 2.5

x =2.5

10-x = 7.5

2.5 of 10% solution and 7.5% of 30% solution

Answer:

17

Step-by-step explanation:

8+2+(3×3-2)=8+2+(9-2)=8+2+7=17

mistake in the first step

firstly we do × and ÷

then + and -

Answer:

See below.

Step-by-step explanation:

When Brian passes Alex they both have travelled the same distance.

Call this distance d.

Let the speed that Brian passes = x miles/hour.

Distance = speed * time  so:

For Alex:

d = (x - 5) * 1.5        ( Alex cycles for 1 + 30 minutes =  1.5 hours)

For Brian:

d = x * 1

So substituting d = x in Alex's equation:

x = 1.5(x - 5)

x = 1.5x - 7.5

7.5 = 0.5x

7/5 / 0.5 = x

15 = x.

ANSWER:

Brian's speed is 15 miles/hour.

Alex's speed is 15 - 5 = 10 miles/hour.

Answer:

0.1294

Step-by-step explanation:

Number of chocolates in box = 38

Number of nuts = 8

Number of caramel = 16

Number of solid chocolate = 14

Since 2 are selected in a row and not replaced, then;

Probability of first being solid chocolate = 14/38

Probability of second being solid chocolate after first one = 13/37

Thus;

P(2 selected in a row being solid chocolate) = 14/38 × 13/37 = 0.1294

9514 1404 393

Answer:

  A.  x = ±2

Step-by-step explanation:

Add 14, then take the square root.

  x^2 -14 +14 = -10 +14

  x^2 = 4

  x = ±√4

  x = ±2

Answer:

A

Step-by-step explanation:

X^2-14=-10

X^2=14-10

X^2=4

√X2=√4

X=±2

Answer:

[tex]Max\ z = 1[/tex]

[tex]Min\ z = -9[/tex]

Step-by-step explanation:

Given

[tex]z = 4x + 5y[/tex]

[tex]x \ge -1[/tex]

[tex]y \le 2x +3[/tex]

[tex]y \le -1[/tex]

Required

The maximum and minimum of z

To do this, we make use of the graphical method

See attachment for graphs of

[tex]x \ge -1[/tex]

[tex]y \le 2x +3[/tex]

[tex]y \le -1[/tex]

The corner points of the function are:

[tex](x,y) = (-1,1)[/tex]

[tex](x,y) = (-1,0)[/tex]

[tex](x,y) = (-1,-1)[/tex]

We have:

[tex]z = 4x + 5y[/tex]

Calculate z with  the above values

[tex]z = 4(-1) + 5(1) = 1[/tex]

[tex]z = 4(-1) + 5(0) = -4[/tex]

[tex]z = 4(-1) + 5(-1) = -9[/tex]

So, we have:

[tex]Max\ z = 1[/tex]

[tex]Min\ z = -9[/tex]

I don't know how you want it solved but, I am giving u -2 I hope this helps

Answer:

Card picked=2

P(factors of 28)={1,2,4,7,14,28}

total cards=4

in percentage=4 x 20 + 20

80+20=100

Therefore 2 in percentage will be

2 x 20 + 20

=40+20=60%

Answer:

156,567

Step-by-step explanation:

782,835 ÷ 5 = 156,567

Answer:

it is 165,567

Step-by-step explanation:

u divide

Perimeter = the sum of the outer sides

#1. P = (2x + 3) + (2x + 3) + (5x - 1) + (5x - 1) + (x - 7)

#2. P = 2(2x + 3) + 2(5x - 1) + (x - 7)

#3. P = 4x + 6 + 10x - 2 + x - 7

#4. P = 15x  - 3

A. Correct - equivalent to #2

B. Incorrect - does not include all of the sides

C. Correct - equivalent to #1

D. Incorrect

E. Incorrect

F. Correct - equivalent to #4

Hope this helps!

Answer:

A, C, F.

Step-by-step explanation:

Answers A, C, and F are all equal and represent the perimeter of the shape.

There are 2 sides that are (2x+3) and (5x-1) in size and 1 side that is (x-7) in size.

Answer:

(6) the letter n : intersection which means the number you will find at the first bracket and has the same number at the other bracket

ANSWER:

the conditions are the angle a is equal to angle c and ab = bc . Hence we need to prove that the triangles is congruent to the triangle cbe. ... angle A =angle C and AB=BC.

Answer:

[tex]=\frac{1}{8568}\ = .00011\\\ =\frac{7}{8568} = .00081[/tex]

Step-by-step explanation:

[tex]5/18\cdot \:4/17\cdot \:3/16\cdot \:2/15\cdot \:1/14=\frac{1}{8568}[/tex]

Answer:

since Sal washed 5 cars in 50 minutes, we can express his time as follow:

[tex] \frac{5 \: cars}{50 \: minutes} [/tex]

simplifying it by diving by 5, we get:

[tex] \frac{1 \: car}{10 \: minutes} [/tex]

Thus the rate will be 10 minutes per car (10 min/car)

Answer:

10 mins / car

Step-by-step explanation:

50 / 5 = 10

Answer:

C. Complex

Step-by-step explanation:

A complex number consists of a real part (-4.8) and an imaginary part (56i)

Answer:

3300cm²

Step-by-step explanation:

30cm+30cm=60cm 60cm is the lengh of the whole joint structure.We will put it in the equation as "a".

heigh stays the same(10cm) because the pieces are not stacked one on top of the other.They are joined on their sides.We will put it as "c".

Widht also stays the same.its 15 cm and we will put it as letter "b".

So

a=60cm

b=15cm

c=10cm

We need to calculate the surface area of the entire joint structure.

1.First thing to do is to calculate the top part which is:

a*b=15*60=900cm²

2.The bootom side is the same 900cm².

3.The front side is:

a*c=60*10=600cm²

4.The back side is the same as front so it is 600cm².

5.The left side is:

c*b=10*15=150cm²

6.The right side is the same as the left and it is 150cm²

Now we just add it up.

S(surface)=900*2+600*2+150*2=3300cm²

If you want the whole exercise in one equation:

S=2*(a*b)+2*(a*c)+2*(b*c)

Answer:

864

Step-by-step explanation:

A=6a^2=6·12^2=864

Answer:

864 in^2

Step-by-step explanation:

2(144+144+144) = 2(432) = 864 in^2.

Hope this helped!