Find the value of the expression 8x^3 if x= -2

Hello!

x² - 4x + 6 = 9 <=>

<=> x² - 4x + 6 - 9 = 0 <=>

<=> x² - 4x - 3 = 0 <=>

<=> x = -(-4)±√(-4)²-4×1×(-3)/2×1 <=>

<=> x = 4±√16+12/2 <=>

<=> x = 4±√28/2 <=>

<=> x = 4±2√7/2 =>

=> x = 4+2√7/2 and x = 4-2√7/2 =>

=> x = 2+√7 and x = 2-√7

The equation has two solutions.

Good luck! :)

Answer:  [tex]x= 2 + \sqrt{7}\\ or \\ x= 2 - \sqrt{7}[/tex]

how i got it?

[tex]x^2 - 4x + 6 = 9[/tex]

*subtract 9 on both sides*

[tex]x^2 - 4x + 6 - 9 = 0[/tex]  ( which turns to) [tex]x^2 - 4x - 3=0[/tex]

a=1 or x, b=-4, c=-3

Step 2: Use quadratic formula with a=1, b=-4, c=-3.

[tex]x= - (-4) + or - \sqrt{-4}x^{2} -4(1)(-3) / 2(1)[/tex]

which turns to: x= 4 + or - √28 divided by 2

the final answer should be [tex]x= 2 + \sqrt{7}\\ or \\ x= 2 - \sqrt{7}[/tex]

Answer:

a). 3/4 kg de papa

Step-by-step explanation:

Given that,

Patata colocada en balanza = 1 1/4 Kg

Flor de papa total quiere = 2 kg

Encontrar,

Se agregará más peso en la báscula para que sea de 2 kg =?

Procedimiento:

Peso requerido para ser colocado = Peso total - peso colocado

= 2 - [tex]1\frac{1}{4}[/tex]

= 2 - 5/4

= (8 - 5)/4

= 3/4 kg

Answer:

7.5 miles per hour

Step-by-step explanation:

Average Speed = Total Distance/Total Time

[tex]\frac{2 \frac{1}{2} }{\frac{1}{3} }[/tex]= 7.5 miles/hour

Answer from Gauthmath

Answer:

Step-by-step explanation:

Please check out the attachments for the solution :)

Answer:

No entendí lo siento

Step-by-step explanation:

Jummm

B)1.2 x is a mathematical expression for the selling price.

The selling price is the charge that a purchaser will pay to purchase a product or a commodity. It's miles a price above the value price and consists of a percentage of income additionally. Cost price is the price at which the seller purchases the product or the commodity.

Maria bought a stock for x dollars.

Cost of stocks = x dollars.

sold it at a profit of 20 %.

The selling price is given below.

= x + 20%

= 1.2x

Learn more about the selling price here: https://brainly.com/question/1153322

#SPJ2

Answer:

[tex]{ \tt{3x + 4(x - 8) - 14}} \\ = { \tt{3x + 4x - 32 - 14}} \\ = { \tt{7x + 46}}[/tex]

Answer:

3x^2y

Step-by-step explanation:

Its common factor it this ^ this symbol represent power

Answer:

it becomes 27 times larger

Step-by-step explanation:

y = k [tex]x^{3}[/tex]

vs.

y = k[tex](3x)^{3}[/tex]

y = k 27 x^3

Answer:

18 is 64 days

20 is 1 37/128

Step-by-step explanation:

I looked it up if I am being completely honest with you but it should be correct

Answer:

2nd

2nd option <cba=<dea

Answer:

B  

as DE=CB

    <C=<D

    <B= <E

Therefore it is congruent

Have a nice day!

Answer:

A. 1/7^8

Step-by-step explanation:

Given

(7^-6) / 7²

Both numerator and denominator has the same base, so just one of the bases will be picked

Division sign changes to minus in indices

(7^-6) / 7²

= 7 ^(-6-2)

= 7^-8

= 1/7^8

Note: a^-b

= 1/a^b

The same rule is used at the last step of the calculation

Answer is

A. 1/7^8

Answer:

Hello,

[tex]16\pi[/tex]

Step-by-step explanation:

[tex]I=\dfrac{Area}{4} =\int\limits^4_0 {\sqrt{16-x^2} } \, dx \\\\Let\ say\ x=4*sin(t),\ dx=4*cos(t) dt\\\\\displaystyle I=\int\limits^\frac{\pi }{2} _0 {4*\sqrt{1-sin^2(t)} }*4*cos(t) \, dt \\\\=16*\int\limits^\frac{\pi }{2} _0 {cos^2(t)} \, dt \\\\=16*\int\limits^\frac{\pi }{2} _0 {\frac{1-cos(2t)}{2}} \, dt \\\\=8*[t]^\frac{\pi }{2} _0-[\frac{sin(2t)}{2} ]^\frac{\pi }{2} _0\\\\=4\pi -0\\\\=4\pi\\\\\boxed{Area=4*I=16\pi}\\[/tex]

Answer:

3x

Step-by-step explanation:

factoring it we get

3x(4x-3)

60° because it's an equilateral triangle

Answer: where's the pic?

Step-by-step explanation:

Answer:

5m-n-4p

4a^2+6x-3

Step-by-step explanation:

3m-4n +7p

-5m +9n -6p

+7m -6n -5p

----------------------

Combine like terms

3m-4n +7p

-5m +9n -6p

+7m -6n -5p

----------------------

(3-5+7)m  +(-4+9-6)n  +(7-6-5)p

5m-n-4p

a^2  -3x +1

a^2   +9x -6

2a^2 +0x +2

----------------------

Combine like terms

a^2  -3x +1

a^2   +9x -6

2a^2 +0x +2

----------------------

(1+1+2)a^2 +(-3+9+0)x +(1-6+2)

4a^2+6x-3

#1

[tex]\\ \sf\longmapsto 3m-4n+7p+(-5m+9n-6p)+7m-6n-5p[/tex]

[tex]\\ \sf\longmapsto 3m-4n+7p-5m+9n-6p+7m-6n-5p[/tex]

[tex]\\ \sf\longmapsto 3m-5m+7m-4n+9n-6n+7p-6p-5p[/tex]

[tex]\\ \sf\longmapsto 5m-n-4p[/tex]

#2

[tex]\\ \sf\longmapsto a^2-3x+1+a^2+9x-6+2a^2+2[/tex]

[tex]\\ \sf\longmapsto a^2+a^2+2a^2-3x+9x+1-6+2[/tex]

[tex]\\ \sf\longmapsto 4a^2+6x-3[/tex]

Answer:

[tex]5\sqrt{5}[/tex]

Step-by-step explanation:

1. [tex]5^2 +10 ^2 = c^2[/tex]

2. [tex]c^2 = 125[/tex]

3. [tex]c = 5\sqrt{5}[/tex]

Answer:

approximately 11.18 inches or [tex]5\sqrt{5[/tex] inches

Step-by-step explanation:

We have to use Pythagorean Theorem for this problem. a^2 + b^2 = c^2, where c is the hypotenuse and a/b are legs of the right triangle.

5^2 + 10^2 = c^2, 25 + 100 = c^2, 125 = c^2, sqrt125 = c

sqrt125 can be simplified to 5sqrt5 (25 * 5 = 125, sqrt25 = 5)

The hypotenuse is approximately 11.18 inches or [tex]5\sqrt{5[/tex] inches.

Given:

The function are:

[tex]f(x)=Kx^2+4x-3[/tex]

[tex]g(x)=2x-7[/tex]

The graph of f(x) intersect the line g(x) at one point.

To find:

The value of K.

Solution:

The graph of f(x) intersect the line g(x) at one point. It means the line g(x) is the tangent line.

We have,

[tex]f(x)=Kx^2+4x-3[/tex]

Differentiate this function with respect to x.

[tex]f'(x)=K(2x)+4(1)-(0)[/tex]

[tex]f'(x)=2Kx+4[/tex]

Let the point of tangency is [tex](x_0,y_0)[/tex]. So, the slope of the tangent line is:

[tex][f'(x)]_{(x_0,y_0)}=2Kx_0+4[/tex]

On comparing [tex]g(x)=2x-7[/tex] with slope-intercept form, we get

[tex]m=2[/tex]

So, the slope of the tangent line is 2.

[tex]2Kx_0+4=2[/tex]

[tex]2Kx_0=2-4[/tex]

[tex]x_0=\dfrac{-2}{2K}[/tex]

[tex]x_0=-\dfrac{1}{K}[/tex]

Putting [tex]x=x_0,g(x)=y_0[/tex] in g(x), we get

[tex]y_0=2x_0-7[/tex]

Putting [tex]x=-\dfrac{1}{K}[/tex] in the above equation, we get

[tex]y_0=2(-\dfrac{1}{K})-7[/tex]

[tex]y_0=-\dfrac{2}{K}-7[/tex]

Putting [tex]x=-\dfrac{1}{K}[/tex] and [tex]f(x)=-\dfrac{2}{K}-7[/tex] in f(x).

[tex]-\dfrac{2}{K}-7=K\left(-\dfrac{1}{K}\right)^2+4(-\dfrac{1}{K})-3[/tex]

[tex]-\dfrac{2}{K}-7=\dfrac{1}{K}-\dfrac{4}{K}-3[/tex]

[tex]-\dfrac{2}{K}-7=\dfrac{-3}{K}-3[/tex]

Multiply both sides by K.

[tex]-2-7K=-3-3K[/tex]

[tex]-2+3=7K-3k[/tex]

[tex]1=4k[/tex]

[tex]\dfrac{1}{4}=K[/tex]

Therefore, the value of K is [tex]\dfrac{1}{4}[/tex].

Answer:

Please check explanations

Step-by-step explanation:

The diameter is twice the height;

if diameter is d and height is h

Then;

d = 2h

But, we know that the radius is half the diameter size. Which means that the diameter is twice the radius

Thus;

2r = 2h

Then r = h

Mathematically the total surface area of a cylinder is;

2pi r (r + h)

substitute h for r

2pi h(h + h)

= 2pi * h * 2h

= 4 pi h^2 (QED)

Answer:

11

Step-by-step explanation:

a+b^2

Let a=2 and b=3

2+3^2

2 + 9

11

Answer: 11

2 + (3 x 3 )

2 + 9

The required answer would be 11 :)

Step-by-step explanation:

Answer: yes

A prime factor is number that can only divided by itself and one

Since, 17 can only be divided by 17 and 1, the student is correct

Step-by-step explanation:

Answer:

Total chairs = 18×22= 396

so no. of extra chairs need = 468-396 = 72

Now( 72/18) rows = 4 rows

Therefore 4 more rows are needed here

Hope it helps you

Answer: 4

Step-by-step explanation:

The amount of chairs in the hall can be found by multiplying 22 by 18 and getting 396. The amount of chairs needed is 468, so 468-396 gets you the amount of chairs still needed and the number 72. There are 18 chairs in each row, and 72/18 is 4. So 4 more rows are needed.

Answer:

sin A = 12 /13

Step-by-step explanation:

Since this is a right triangle, we can use trig functions

sin A = opp / hyp

sin A = 12 /13

Answer:

-4/5

Step-by-step explanation:

sin theta = opp/ hyp

sin theta = -3 /5

Using the Pythagorean theorem

opp ^2 + adj ^2 = hyp ^2

(-3) ^2 + adj ^2 = 5^2

9+ adj ^2 = 25

adj ^2 = 25 - 9

adj ^2 = 16

Taking the square root of each side

adj = ±4

Since we are in the 3rd quadrant  sin and cos are both negative so adj must be negative

adj = -4

cos theta = adj / hyp

cos theta = -4/5

[tex]\sf \: {x}^{2} + 4xy - 21 {y}^{2} [/tex]

[tex]\sf \: Rewrite \: the \: equation⟹( {x}^{2} - 3xy) + (7xy - 21y {}^{2} )[/tex]

[tex]\sf \: 1)( {x}^{2} - 3xy) = x(x - 3y)[/tex]

[tex]\sf2) \: (7xy - 21 {y}^{2} ) = 7y(x - 3y)[/tex]

[tex]\sf \: Now \: the \: equation \: becomes \: ⟹ \\ \sf \: x(x - 3y) + 7y(x - 3y)[/tex]

[tex]\sf \: Factor \: out \: the \: common \: term \: (x - 3y) \\ \sf =( x - 3y) + (x + 7y) \\ [/tex]

Answer ⟶ [tex]\boxed{\sf {B) (x-3y)(x+7y)}}[/tex]

Answer: 3000 stamps

Step-by-step explanation:

Given

Chris and Josh have 1800 stamps

Josh and Jessica have 2200 stamps

Jessica and Chris have 2000 stamps

Suppose Chris, Josh, and Jessica have [tex]x,y, \text{and}\ z[/tex] stamps

[tex]\therefore x+y=1800\quad \ldots(i)\\\Rightarrow y+z=2200\quad \ldots(ii)\\\Rightarrow z+x=2000\quad \ldots(iii)\\\text{Add (i), (ii), and (iii)}\\\Rightarrow 2(x+y+z)=1800+2200+2000\\\Rightarrow x+y+z=3000[/tex]

Thus, all three have 3000 stamps