Show that the equation x^2−4x+y^2+6y+z^2−4=0 represents a sphere, then find its center and radius.

Answer:

[tex](f+g)(x) = 3x^2 - 6[/tex]

Step-by-step explanation:

[tex]f(x) = 2x^2 + 1, \ g(x) = x^2 - 7\\\\(f +g)(x) = f(x) + g(x) \\\\(f+g)(x) = 2x^2 + 1 + x^2 - 7 \\\\(f+ g)(x) = 3x^2 - 6[/tex]

Answer:

-4/3

Step-by-step explanation:

-3 x (-2/3)²

= -3 x (4/9)

= -4/3

Answer: f(3)=-7

Step-by-step explanation:

To evaluate f(3), we want to plug in x=3 into f(x)=-4x+5.

f(3)=-4(3)+5       [multiply]

f(3)=-12+5          [add]

f(3)=-7

Now, we know that f(3)=-7.

Answer:

30 seconds

Step-by-step explanation:

→ Work out how many floors it's going to travel

15 - 3 = 12 floors

→ Work out how many meters 12 floors is

12 × 5 = 60 meters

→ Work out how long that will take

60 ÷ 2 = 30 seconds

Answer:

[tex]f^{-1}[/tex] (x) = [tex]\frac{5x}{x-2}[/tex]

Step-by-step explanation:

let y = f(x) and rearrange making x the subject

y = [tex]\frac{2x}{x-5}[/tex] ( multiply both sides by x - 5 )

y(x - 5) = 2x ← distribute left side

xy - 5y = 2x ( subtract 2x from both sides )

xy - 2x - 5y = 0 ( add 5y to both sides )

xy - 2x = 5y ← factor out x from each term on the left side )

x(y - 2) - 5y ← divide both sides by y - 2

x = [tex]\frac{5y}{y-2}[/tex]

Change y back into terms of x with x = [tex]f^{-1}[/tex] (x) , then

[tex]f^{-1}[/tex] (x) = [tex]\frac{5x}{x-2}[/tex]

Look into the image. I hope it helps❤

Answer:

7 students

Step-by-step explanation:

1+2+4=7students

Answer:

152-88 = 64

Step-by-step explanation:

Answer:

x > 23/5

Step-by-step explanation:

2x+ 3(x+2)>17

2x + 3x + 6 >17

5x >23

x > 23/5

Answer:

She should have included an exponent of 2 on the 3

Step-by-step explanation:

The factor tree can be presented as follows;

                [tex]{}[/tex]                                90

[tex]{}[/tex]                                                  ↓

[tex]{}[/tex]                                     9          ↔            10

[tex]{}[/tex]                                     ↓                           ↓

[tex]{}[/tex]                                3  ↔  3                  2  ↔  5

Therefore, the prime factorization of 90 is equal to 90 = 3 × 3 × 2 × 5

She should have wrote, 90 = 3² × 2 × 5

Therefore, the error is that she should have included an exponent of 2 on the 3.

Answer:

B

✔ She should have included an exponent of 2 on the 3.

Step-by-step explanation:

E2021

Answer:

The value of x is 8 .

Step-by-step explanation:

It is known that EF = x cm , GH = (x + 6) cm , RS = 16 cm and NP = 28 cm . Knowing that EF ,GH , RS , and NP are, in that order, proportional segments, determine the value of x .

As EF, GH, RS and NP are in proportion

So,

EF : GH = RS : NP

[tex]\frac{x}{x+6}=\frac{16}{28}\\\\7 x = 4 (x + 6)\\\\7 x = 4 x + 24 \\\\3 x = 24 \\\\x = 8[/tex]

Answer:

n=5

Step-by-step explanation:

by using

n=(an-a)/a+1

substituting values

n= 7.2-(-7.2)/3.6 +1

n=5

Answer:

Answer:

[tex]a \div (b + c) = (a \div b) + (a \div c) \\ 6 \div (5 + 7) = (6 \div 5) + (6 \div 7) \\ 0.5 = 1.2 + 0.86 \\ 0.5 = 2.06[/tex]

Answer:

Step-by-step explanation:

1) 2/9 = 185/x

  2x = 1665

x = 832.5 or 8.325 meters

2) unit rate is the cost of one unit

i.e a dozen eggs cost $1.20 that

would be 10 cents each

3) 300 tissues for $3.75 vs. 250 for $2.99

one is 1.24 cents per tissue

the other 1.19 ... the 250 package is a better buy

Answer:

a. -2

c. -1

Step-by-step explanation:

these are the only values for x, where the 2 equations deliver the same y value.

in case of a. y = -2×-2 - 1 = 4 - 1 = 3

and y = 3¹ = 3

c. y = -2×-1 - 1 = 2 - 1 = 1

y = 3⁰ = 1

Answer:

area of parallelogram=base *height

Answer:

area =36cm²

Step-by-step explanation:

area of parallelogram= b×h

Answer:

76°

Step-by-step explanation:

180-(2*52)

= 180-104

= 76

Answered by GAUTHMATH

Answer:

-37

Step-by-step explanation:

-155-20-14-133-73=-395

190+170=360

-395+360=-37

Answer:

R = (-3, 8).

Step-by-step explanation:

Recall the midpoint formula:

[tex]\displaystyle M=\left(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\right)[/tex]

Where M is the midpoint, (x₁, y₁) is one point and (x₂, y₂) is another.

We are given that Q is the midpoint of PR, where P = (11, -2) and Q = (4, 3) and we want to find the coordinates of R.

Substitute Q for M and let P(11, -2) be (x₁, y₁). Hence:

[tex]\displaystyle (4, 3)=\left(\frac{11+x_2}{2}, \frac{-2+y_2}{2}\right)[/tex]

Split into two separate equations:

[tex]\displaystyle \frac{11+x_2}{2}=4\text{ and } \frac{-2+y_2}{2}=3[/tex]

Solve for each case:

[tex]\displaystyle 11+x_2=8\Rightarrow x_2=-3[/tex]

[tex]\displaystyle -2+y_2=6\Rightarrow y_2=8[/tex]

Therefore, our second point (x₂, y₂) is (-3, 8).

Hence, R = (-3, 8).

Answer:

(15/2),(1/2)

Step-by-step explanation:

(x1 + x2 / 2)  ,   (y1 + y2) / 2)

(11 + 4 / 2) , (-2 + 3 / 2)

(15/2) , (1/2)

Answer: The quotient of 28 and 4 minus the sum of a number and 7

Step-by-step explanation:

Answer:

[tex]{ \tt{sum = \frac{a(r {}^{n - 1} )}{n - 1} }} \\ 27 = \frac{a(r {}^{2 - 1} )}{2 - 1} \\ { \bf{27 = ar - - - (i)}} \\ \\ 54 = \frac{a( {r}^{3 - 1} )}{3 - 1} \\ { \bf{108 = a {r}^{2} - - - (ii) }} \\ { \tt{(ii) \div (i) : }} \\ r = \frac{108}{27} \\ { \bf{common \: ratio = 4}} \\ { \bf{first \: term = \frac{27}{4} }}[/tex]

Answer:

C.7, -2

Step-by-step explanation:

A quadratic equation is a polynomial of degree two. A quadratic equation is in the form:

ax² + bx + c = 0; where a, b, c are constants.

Quadratic equation can be solved using different methods, such as completing the square method, quadratic formula.

Solving the equation 2x² - 10x - 20 = 8 using completing the square:

2x² - 10x - 20 = 8

2x² - 10x = 28

Divide through by 2, to make the coefficient of x² to be 1:

x² - 5x = 14

Add to both sides, the square of half of the coefficient of x [i.e. (-5/2)² = 6.25]

x² - 5x + 6.25 = 14 + 6.25

(x - 2.5)² = 20.25

taking square root of both sides:

x - 2.5 = √20.25

x - 2.5 = ±4.5

x = 2.5 ± 4.5

x = 2.5 + 4.5; or x = 2.5 - 4.5

x = 7 or x = -2

The line graph (A) represents the expression 5/2 + 3 the first term is 2 and-a-half units, and the second term is 3 units option (A) is correct.

It is defined as the representation of the numbers on a straight line that goes infinitely on both sides.

We have an expression:

= 5/2 + 3

Here 5/2 = 2.5 = 2 and half

= 2.5 + 3

The first arrow should indicate the 2 and-a-half unit

And the second arrow should represent the 3 unit

The line graph(A) represents the above situation or expression.

Thus, the line graph (A) represents the expression 5/2 + 3 the first term is 2 and-a-half units, and the second term is 3 units option (A) is correct.

Learn more about the number line here:

brainly.com/question/13189025

#SPJ1

Answer:

63/70 = 9 : 10

Step-by-step explanation:

Given ratio:

9/10

a 70/63

= 10/9

= 10 : 9

b 19/70

= 19:70

c 19/20

= 19 : 20

d 63/70

= 9/10

= 9 : 10

The equivalent ratio to 9/10 = 63/70

= 9 : 10

Answer:

Step-by-step explanation:

Eq. 1 )   −5x−3y−9=0

Eq. 2)   4x−18y−54=0

there are two routes to solve this,   Substitution or  elimination,  I'll go for the 2nd one because I can see that the y values are a multiple of each other :)

    6 *( −5x−3y−9=0 )

Eq. 3) -30x -18y =54

subtract Eq. 2 from Eq. 3  :)

-30x -18y =54

-( 4x−18y=54)

-34x = 0

so according to the equations then x =0 but,  that's not really a full answer, so now we should go back and try the other method, substitution,

then:

-5x = 9 +3y

x = - 9/5 + (-3/5)y

now plug that into Eq. 2

4( - 9/5 + (-3/5)y ) - 18y = 54

-36/5 + (-12/5)y -18y = 54

(-12/5)y - (90/5)y = 54+36/5

-(102/5)*y =270/5+36/5

-(102/5)y = 306/5

y = (-5/102)*(306/5)

y = -306/102

y = -3

then plug in for either equation

-5x-3( -3) = 9

-5x + 9 = 9

-5x = 0

x = 0

now we have the full answer

check it by plugging in both x and y into the 2nd equation

4(0) - 18(-3) = 54

54= 54

this seems good  

Answer:

b

Step-by-step explanation:

Answer:

2400

Step-by-step explanation:

2244 is the final price. it includes the VAT based on the actual sale price. and that is then actually 15% lower than the originally marked price.

so, let's calculate backwards :

2244 = 100% sale price + 10% VAT = 110%

1% = 2244 / 110 = 20.40

100% (actual sale price) = 20.40×100 = 2040

now, because of the 15% discount, these 2040 are only 85% of the originally marked price.

2040 = 85%

1% = 2040 / 85 = 24.00

100% (the original marked price) = 24×100 = 2400

Answer:

9, 10, 11, 12

Step-by-step explanation:

Let the consecutive numbers be:

x, x+1, x+2, x+3

Greatest of the numbers will be: x + 3

x+x+1+x+2+x+3 = 3(x+3) + 2

4x + 6 = 3(x+4) + 2

4x + 6 = 3x + 12 + 2

4x + 6 = 3x + 14

Collect like terms

4x - 3x = 14 - 6

x = 8

x +1 = 8+ 1 = 9

x + 2 = 8 + 2 = 10

x + 3 = 8 + 3 = 11

x + 4 = 8 + 4 = 12