Help me please I will give you brainliest btw I need this asap

Step-by-step explanation:

8 cos 80° cos 140° cos 160°

4 (2 cos 80° cos 140°) cos 160°

4 cos 160° (2 cos 80° cos 140°)

Use product to sum formula.

4 cos 160° (cos 60° + cos 220°)

4 cos 160° (½ + cos 220°)

2 cos 160° + 4 cos 220° cos 160°

2 cos 160° + 2 (2 cos 220° cos 160°)

Use product to sum formula again.

2 cos 160° + 2 (cos 60° + cos 380°)

2 cos 160° + 2 (½ + cos 380°)

2 cos 160° + 1 + 2 cos 380°

2 cos 160° + 1 + 2 cos 20°

Use shift identity cos(180 − θ) = -cos θ.

-2 cos 20° + 1 + 2 cos 20°

1

Our question that we have at hand here is 8(cos 80°)(cos 140°)(cos 160°). We need to convert that into 'decimal form' to prove that it equals 1. However decimal form doesn't generally give us a decimal, in this case.

Let's start by using the identity cos(s)cos(t) = cos(s + t) + cos(s - t) / 2. In this case we are looking particularly at the expression (cos 80°)(cos 140°), where s = 80, and t = 140.

[tex]\cos \left(80^{\circ \:}\right)\cos \left(140^{\circ \:}\right)=\frac{\cos \left(80^{\circ \:}+140^{\circ \:}\right)+\cos \left(80^{\circ \:}-140^{\circ \:}\right)}{2}[/tex]

[tex]=8\cdot \frac{\cos \left(80^{\circ \:}+140^{\circ \:}\right)+\cos \left(80^{\circ \:}-140^{\circ \:}\right)}{2}\cos \left(160^{\circ \:}\right)[/tex]

[tex]= 4\cos \left(160^{\circ \:}\right)\left(\cos \left(220^{\circ \:}\right)+\cos \left(-60^{\circ \:}\right)\right)[/tex]

To further simplify this expression, we know that cos(- 60°) = cos(60°). This may not seem like a very effective step, but we can apply a few trivial identities here. Remember that cos(60°) = 1 / 2,

[tex]4\cos \left(160^{\circ \:}\right)\left(\cos \left(220^{\circ \:}\right)+\frac{1}{2}\right)[/tex]

[tex]= 4(0.25)\\= 1[/tex]

And hence we proved that 8(cos 80°)(cos 140°)(cos 160°) in decimal form, = 1.

A. x ≤ - 9 or x ≥ 9

x² ≥ 81

| x | ≥ 9

x ≥ 0 => x ≥ 9 => x ∈ [ 9 ; + oo)

x < 0 => x ≤ - 9 => x ∈ ( -oo ; - 9 ]

x ∈  ( -oo ; - 9 ] ∪ [ 9 ; + oo)

Answer:

4x-6

Step-by-step explanation:

Six less than four times a number is four times x because times is multiplying and then subtracting six because less means minus (subtraction)

Answer:

4(x+y)

Step-by-step explanation:

x+y is one side length and there are 4 side lengths.

It depends on which culture you're looking at to be honest. But in the current environment, one item that is fairly prevalent is the coronavirus facemask. You could say it symbolically represents the idea of trying to stay safe and it represents a new norm (that many may consider strange since people are used to seeing each other's faces).

Answer:

The 3 in that longest number I have seen in the world is 30 Billion.

Step-by-step explanation:

Million: 6 places before

Billion: 9 places before

Hope this helps!

Answer:

The answer is

Step-by-step explanation:

First of all factor out the perfect square out.

In this question the perfect squares are 4 and x²

So we have

Separate the radicals

That's

Simplify

So we have

We have the final answer as

Hope this helps

Answer:

[tex]2n \sqrt{6n} [/tex]

Step-by-step explanation:

[tex] \sqrt{24n {}^{3} } [/tex]

[tex] \sqrt{2 {}^{2} } \times 6 {n}^{3} [/tex]

[tex] \sqrt{ {2}^{2} } \times 6n {}^{2} \times n[/tex]

[tex] \sqrt{2 {}^{2} } \sqrt{n {}^{2} } \sqrt{6n} [/tex]

[tex]2 \sqrt{n {}^{2} } \sqrt{6n} [/tex]

[tex]2n \sqrt{6n} [/tex]

2n square root 6n

[tex]2n \sqrt{6n} [/tex]

Hope this helps.....

Answer:

Step-by-step explanation:

[tex]4z^2 - 3z - 4​\\z =2[/tex]

Substitute 2 for z in the given equation

[tex]4(2)^2 - 3(2) -4\\[/tex]

Follow the PEMDAS order of operations

[tex]\mathrm{Calculate\:exponents}\:\left(2\right)^2\::\quad 4\\=4\cdot \:4-3\left(2\right)-4\\\\\mathrm{Multiply\:and\:divide\:\left(left\:to\:right\right)}\:4\times\:4\::\quad 16\\=16-3\left(2\right)-4\\\\\mathrm{Multiply\:and\:divide\:\left(left\:to\:right\right)}\:3\left(2\right)\::\quad 6\\=16-6-4\\\\\mathrm{Add\:and\:subtract\:\left(left\:to\:right\right)}\:16-6-4\::\quad 6[/tex]

Answer:

Step-by-step explanation:

Plug in z = 2 in the expression

4z² - 3z - 4 = 4*2² - 3*2 -4

                 = 4*4 - 6 - 4

                 = 16 - 6 - 4

                 = 10 - 4

                 = 6

Answer:

  29.2%

Step-by-step explanation:

The fraction of students with black hair is 7/24. To convert that to a percentage, multiply by 100%.

 7/24×100% = 29.1666(repeating)% ≈ 29.2%

Answer:

x=  [tex]\frac{1}{2}[/tex]go+23

Step-by-step explanation:

Answer:

6^2 + 3^2 = sqrt 45

the answer is the sqrt of 45

Step-by-step explanation:

Answer:

[tex] 3\sqrt{5} [/tex]

Step-by-step explanation:

Use the distance formula and the coordinates of the points.

The upper left point is (-5, 3).

The lower right point is (-2, -3)

[tex] d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} [/tex]

[tex] d = \sqrt{(-2 - (-5))^2 + (-3 -3)^2} [/tex]

[tex] d = \sqrt{3^2 + (-6)^2} [/tex]

[tex] d = \sqrt{9 + 36} [/tex]

[tex] d = \sqrt{45} [/tex]

[tex] d = \sqrt{9 \times 5} [/tex]

[tex] d = 3\sqrt{5} [/tex]

Answer:

Following are the answer to this question:

Step-by-step explanation:

In the given-question, the information is missing. first, we declare the missing information, after that we define its solution:

Missing information:

plotting the Points  (2, 0), (2, 4), (2, 1), and (2, -1).

solution:

please find the attachment.

In the given attachment file, all the points lie within the same line, which indicates its points, and the set may be interpreted throughout the form of (2,y), or even the points may also be placed on the line x=2.

Answer:

My answer to the question is option B

Answer:

hmmmm Option A for me

Step-by-step explanation:

Answer:

Son of 15 years $180

Son of 10 years $120

Step-by-step explanation:

15 + 10 = 25

   25          300

   15              x = 300*15/25

                    x = 180

   25          300

   10              x = 300*10/25

                    x = 120

Son of 15 years $180

Son of 10 years $120

Answer:

Hey there!

A line parallel to y=-4x+3 would have a slope of -4.

Point slope form: y-2=-4(x+3)

Simplify: y=-4x-10

Let me know if this helps :)

Answer:

A

Step-by-step explanation:

So we want an equation that is parallel to:

[tex]y=-4x+3[/tex]

And passes through:

[tex](-3,2)[/tex]

First, since we want the equation to be parallel to the first, the slope must be -4. This is because parallel lines have the same slope.

Now that we know the slope of our equation is -4, we can use the point-slope form to figure out the rest.

The point-slope form is:

[tex]y-y_1=m(x-x_1)[/tex]

m is -4. Let (-3,2) be x₁ and y₁. Thus:

[tex]y-2=-4(x--3)[/tex]

Simplify:

[tex]y-2=-4(x+3)[/tex]

Distribute:

[tex]y-2=-4x-12[/tex]

Add 2 to both sides:

[tex]y=-4x-10[/tex]

So our answer is A :)

Answer:

[tex]\huge \boxed{h=\frac{2A}{a+b} }[/tex]

[tex]\rule[225]{225}{2}[/tex]

Step-by-step explanation:

[tex]\displaystyle A=\frac{1}{2} \cdot (a+b) \cdot h[/tex]

Multiplying both sides by 2:

[tex]2A=(a+b) \cdot h[/tex]

Dividing both sides by (a + b):

[tex]\displaystyle \frac{2A}{a+b} =h[/tex]

[tex]\rule[225]{225}{2}[/tex]

Area of square = 36 unit²

Perimeter of square[tex].[/tex]

◈ Side of square :

[tex]:\implies\sf\:Area=(side)^2[/tex]

[tex]:\implies\sf\:36=(side)^2[/tex]

[tex]:\implies\sf\:side=\sqrt{36}[/tex]

[tex]:\implies\bf\:side=6\:unit[/tex]

◈ Perimeter of square :

[tex]:\implies\sf\:perimeter=4\times (side)[/tex]

[tex]:\implies\sf\:perimeter=4\times 6[/tex]

[tex]:\implies\underline{\boxed{\bf{\purple{perimeter=24\:unit}}}}[/tex]

x^2-4x+4=0

now;

x^2-4x=0-4

x^2-4x=-4

x(x-4)=-4

x^2-4x+4

Answer: The sample mean is more than the population mean by 3.5

=======================================================

Explanation:

To get the population mean, first add up all the population values

4+6+7+11+12+18+26+23+14+31+22+12 = 186

Then divide that over 12 as there are 12 values in the population

186/12 = 15.5

The population mean is 15.5

----------

The sample mean is computed the same way

add the values = 11+31+22+12 = 76

Divide the sum by 4 = 76/4 = 19

The sample mean is 19

The sample mean is larger by 19 - 15.5 = 3.5

Answer:

n + 6(3/10)

Step-by-step explanation:

6(3/10) is written as a mixed number

Answer:

x+6.3

Step-by-step explanation:

x+6.3

Answer:

Step-by-step explanation:

Third angle = 180 - (40 + 60)

                   = 180 - 100

                   =  80°

When you subtract the sum of 40 and 60 from 180, you will get the third angle.

Answer:

[tex]$-\frac{1}{4} (-2x-9+\sqrt{65})(2x+9+\sqrt{65})$[/tex]

Step-by-step explanation:

We have a second-degree polynomial:

I will find the roots (y = 0) completing the square:

[tex]$x^2+9x+\frac{81}{4}-\frac{81}{4}+4=0$[/tex]

[tex]$\left(x+\frac{9}{2} \right)^2 -\frac{81}{4} +4 =0$[/tex]

[tex]$\left(x+\frac{9}{2} \right)^2 -\frac{81}{4} +\frac{16}{4} =0$[/tex]

[tex]$\left(x+\frac{9}{2} \right)^2 -\frac{65}{4} =0$[/tex]

[tex]$\left(x+\frac{9}{2} \right)^2 =\frac{65}{4} $[/tex]

[tex]$\left(x+\frac{9}{2} \right)^2 =\pm \sqrt{\frac{65}{4} } $[/tex]

[tex]$x =-\frac{9}{2} \pm \frac{\sqrt{65} }{2} $[/tex]

[tex]$x =\frac{-9 \pm \sqrt{65} }{2} $[/tex]

[tex]$\boxed{x_1 =\frac{-9 + \sqrt{65} }{2}} $[/tex]

[tex]$\boxed{x_2 =\frac{-9 - \sqrt{65} }{2}} $[/tex]

Answer:

(a+2)(a-12)

Step-by-step explanation:

[tex]a^2-10a-24\\\\\mathrm{Break\:the\:expression\:into\:groups}\\=\left(a^2+2a\right)+\left(-12a-24\right)\\\\\mathrm{Factor\:out\:}a\mathrm{\:from\:}a^2+2a\mathrm{:\quad }a\left(a+2\right)\\\\\mathrm{Factor\:out\:}-12\mathrm{\:from\:}-12a-24\mathrm{\\:\quad }-12\left(a+2\right)\\=a\left(a+2\right)-12\left(a+2\right)\\\\\mathrm{Factor\:out\:common\:term\:}a+2\\=\left(a+2\right)\left(a-12\right)[/tex]

Answer:

(a + 2)(a - 12)

Step-by-step explanation:

a^2 - 10a - 24

using splitting method

a^2 - 12a + 2a - 24

taking separate common from both pairs

a(a - 12) + 2(a - 12)

(a + 2)(a - 12)

Answer:

A

Step-by-step explanation:

They are all straight paths with end points but a line is never ending  but it is still two dimensional

Answer:

D - Are One dimensional

Step-by-step explanation:

Line , Line segments and Ray's are all one dimensional objects

Answer:

-4

Step-by-step explanation:

Step 1: Subtract 7 from both sides.

−2x+7−7=15−7

−2x=8

Step 2: Divide both sides by -2.

−2x

−2

=

8

−2

x=−4

Answer: negative

Step-by-step explanation: Whenever you are adding negative

numbers together, you will always get a negative number.

For example, (-1) + (-1) will give you -2.

In the same way, (-5) + (-4) gives you -9.

Answer: negaitive

When you add a negative plus a negative you always get another negative

Answer: 3/16

Step-by-step explanation:

- you divide 3/16 which gets you to the answer of 0.1875

A fraction is a way to describe a part of a whole. The size of the bolt that will best fit in the wrench is 3/16 inches.

A fraction is a way to describe a part of a whole. such as the fraction ¼ can be described as 0.25.

Jaylon has a wrench labeled 0.1875 inch and bolts labeled in fractions of an inch.

Now, the size of the bolt that will best fit in the wrench will be the bolt of size same as the wrench. Therefore, if we rewrite the size of the wrench it will be,

Size of the bolt = Size of the wrench

                         = 0.1875 inches

                         = 1875/10000 inches

Divide both the numerator and the denominator by 625

                         = 3/16 inches

Hence, the size of the bolt that will best fit in the wrench is 3/16 inches.

Learn more about Fraction here:

https://brainly.com/question/1301963

#SPJ2

Answer:

5/3

Step-by-step explanation:

x*0.9=1.5

x=15/9

x=5/3

Lets solve your question step by step:-

Given,

0.9*x = 1.5

0.9x = 1.5

=}  0.9x/0.9 = 1.5/0.9

x = 1.666667

So,

9 times 1.666667 (x) is 1.5

Hope it helps :)