Three men can build a wall in 8 days. How long will it take them if they have the help of 2 boys? Assume that each boy works half as fast as each man.

(with explanation pls)​

Answer:

i think the answet is 0.625

Answer:

x=2 is incorrect

Step-by-step explanation:

Y(2)=(3/4)*x^2=(3/4)*4=3

Consider this example: say we want to convert x = 11 0101 1001₂ to base 3.

The binary expansion of x is

x = 1×2⁹ + 1×2⁸ + 1×2⁶ + 1×2⁴ + 1×2³ + 1×2⁰

which in base 10 reduces to

x = 512 + 256 + 64 + 16 + 8 + 1 = 857

Recall the first several powers of 3:

3⁰ = 1; 3¹ = 3; 3² = 9; 3³ = 27; 3⁴ = 81; 3⁵ = 243; 3⁶ = 729

Now it's a matter of computing quotients and remainders. Pick the largest power of 3 that fits into the target number, then check the remainder and repeat.

• How many times does the 729 go into 857? 1 time, and it leaves a remainder of 128, or

857 = 1×729 + 128 = 1×3⁶ + 128

• How many times does 81 go into 128? Also 1 time, so

128 = 1×81 + 47 = 1×3⁴ + 47

• How many times does 27 go into 47? Also 1 time,

47 = 1×27 + 20 = 1×3³ + 20

• How many times does 9 go into 20? 2 times,

20 = 18 + 2 = 2×9 + 2 = 2×3² + 2

• How many times does 1 go into 2? Also 2 times,

2 = 2 + 1 = 2×1 + 0 = 2×3⁰

So we found

857 = 1×3⁶ + 1×3⁴ + 1×3³ + 2×3² + 2×3⁰

which is the ternary expansion of x,

x = 1 011 202₃

Answer:  Choice D

15(cos85° + i sin85°)

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Explanation:

Let's say we had these two general complex numbers, which are in polar form.

[tex]z_1 = r_1*\left(\cos(\theta_1)+i*\sin(\theta_1)\right)\\\\z_2 = r_2*\left(\cos(\theta_2)+i*\sin(\theta_2)\right)\\\\[/tex]

We can abbreviate them into the shorthand form

[tex]z_1 = r_1*\text{cis}(\theta_1)\\\\z_2 = r_2*\text{cis}(\theta_2)\\\\[/tex]

The notation "cis" stands for "cosine i sine".

Now that we have those complex numbers set up, multiplying them is as simple as saying this:

[tex]z_1*z_2 = (r_1*r_2)*\text{cis}(\theta_1+\theta_2)[/tex]

We do two basic things:

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

With all that in mind, let's tackle the problem your teacher gave you.

The given complex numbers

[tex]z_1 = 5*\left(\cos(15^{\circ})+i*\sin(15^{\circ})\right)\\\\z_2 = 3*\left(\cos(70^{\circ})+i*\sin(70^{\circ})\right)\\\\[/tex]

abbreviate into

[tex]z_1 = 5*\text{cis}(15^{\circ})\\\\z_2 = 3*\text{cis}(70^{\circ})\\\\[/tex]

then those multiply to

[tex]z_1*z_2 = (r_1*r_2)*\text{cis}(\theta_1+\theta_2)\\\\z_1*z_2 = (5*3)*\text{cis}(15+70)\\\\z_1*z_2 = 15\text{cis}(85^{\circ})\\\\z_1*z_2 = 15\left(\cos(85^{\circ})+i\sin(85^{\circ})\right)\\\\[/tex]

which is why choice D is the final answer.

Step-by-step explanation:

Given

x = 3/4

y = -2/5

Now

X + y = 3/4 - 2/5

[tex] \frac{3 \times 5 - 2 \times 4}{20} [/tex]

[tex] = \frac{15 - 8}{20} [/tex]

[tex] = \frac{7}{20} [/tex]

Answer:

7/20

Step-by-step explanation:

x=3/4

y= -2/5

x+y=?

to get the sum, plug in x=3/4 into the x and y= -2/5 into the y

1. x + y = ?

2. 3/4 + (- 2/5) = ?

3. 3/4 - 2/5 =?

4. find the lcm of 4 and 5 to get the common denominator (in this case, the lcm of 4 and 5 is 20)

5. multiply 3/4 by 5 (numerator and denominator) and 2/5 by 4 (numerator and denominator)

6. 15/20 - 8/20 = 7/20

the answer is 7/20

hopefully this answer can help you to answer the next question.

Answer: (a): Good course, (b): Bad course

Step-by-step explanation:

Firstly, because the standard deviation of the good course results is lower, there is less variation so he performs more consistently there.

Secondly, the trick with the second question is that while the mean of the bad course is slightly less, the standard deviation is quite a lot higher than that of the good course, so it's more likely that the highest single test score belongs to the bad course.

Answer:

I am not sure but it may be option c .

Step-by-step explanation:

I chose option c because in parallelogram the opposite sides are parallel .

Answer:

y=2x-8

Step-by-step explanation:

Hi there!

We want to find an equation of the line parallel to y=2x-4 but has the same x intercept as 3x-4y=12

Parallel lines have the same slope, but different y intercepts

In y=2x-4, which is written in y=mx+b form, m is the slope and b is the y intercept

2 is in the place of where the slope would be, so the slope of that line is 2

That means the slope of the line parallel to it would also have a slope of 2

Here is the equation of the parallel line so far:

y=2x+b

We need to find b, the y intercept

Typically, we'll substitute a point into the equation to solve for b, but we don't have a point, yet

We're given that the new line has the same x intercept as 3x-4y=12

The x intercept is the point where the line passes through the x axis, and so the value of y at that point is 0

Let's substitute 0 for y in 3x-4y=12 and solve for x to find the x intercept

3x-4(0)=12

Multiply

3x=12

Divide both sides by 3

x=4

So the value of the x intercept is 4. As a point, it's (4,0)

So now substitute the values of the point (4,0) into y=2x+b to find b

0=2(4)+b

Multiply

0=8+b

Subtract 8 from both sides

-8=b

Substitute -8 as b into the equation

y=2x-8

Hope this helps!  

Answer:

The expression for the height of the solid is:

[tex]\displaystyle h = x^2+x-9[/tex]

Step-by-step explanation:

Recall that the volume of a rectangular solid is given by:

[tex]\displaystyle V = \ell wh[/tex]

Where l is the length, w is the width, and h is the height.

We know that the volume is given by the polynomial:

[tex]\displaystyle V = 3x^4-3x^3-33x^2+54x[/tex]

And that the length and width are given by, respectively:

[tex]\displaystyle \ell = 3x \text{ and } w =x-2[/tex]

Substitute:

[tex]\displaystyle 3x^4-3x^3-33x^2+54x=(3x)(x-2)h[/tex]

We can solve for h. First, divide both sides by 3x:

[tex]\displaystyle \frac{3x^4-3x^3-33x^2+54x}{3x}=(x-2)h[/tex]

Divide each term:

[tex]\displaystyle x^3-x^2-11x+18=(x-2)h[/tex]

To solve for h, divide both sides by (x - 2):

[tex]\displaystyle h = \frac{x^3-x^2-11x+18}{x-2}[/tex]

Since this is a polynomial divided by a binomial in the form of (x - a), we can use synthetic division, where a = 2. This is shown below. Therefore, the expression for the height of the solid is:

[tex]\displaystyle h = x^2+x-9[/tex]

Answer:

1 hour 33 minutes

Step-by-step explanation:

distance/speed= time

d =800/600

d=1.33

The aeroplane takes 1.33 hours to traverse a distance of 800 km.

Speed is the rate at which an object's position changes, measured in meters per second. For example, if an object starts at the origin, and then moves three meters in three seconds, its speed is one meter per second. The equation for speed is simple: distance divided by time

Given here: An airplane flies a distance of 800 km with an average speed of 600 km/h

Thus the time taken by the aeroplane to cover that distance is

t=800/600

t=4/3

t=1.33 hours

Hence, The aeroplane takes 1.33 hours to traverse a distance of 800 km.

Learn more about the speed of an object here:

https://brainly.com/question/28224010

#SPJ2

Answer:

I'm pretty sure it's the 3rd option

Answer:

first option is correct

Step-by-step explanation:

because there are less no. on negative side than on positive one

Answer:

each costumer owe $35.40

Step-by-step explanation:

so, u get 247.79÷7 (cuz it is 7 people)

u get 35.40.

to check just get 35.40×7 and u will revice their total.

Answer:

Step-by-step explanation:

Applying the midpoint formula to the points (a, 0) and (0, a) looks like this:

[tex]M=(\frac{a+0}{2},\frac{0+a}{2})[/tex] which simplifies to

[tex]M=(\frac{a}{2},\frac{a}{2})[/tex]

Answer: The range is  [tex]\{y \in \mathbb{R}\ | \ y \le -6\}[/tex]

Explanation:

The parabola opens down, forming a "frowny face" in a way (just without the eyes). Or you can think of it as a hill or mountain. This means that the vertex (-3,-6) is at the top of that mountain. It's the highest point of that parabola.

The range is the set of all possible y values. We see that y = -6 is the largest it can get. So y = -6 or y is smaller than this. We would then write [tex]y \le -6[/tex] to describe all the possible y values.

Therefore, the range is [tex]\{y \in \mathbb{R}\ | \ y \le -6\}[/tex]

This translates to "y is a real number such that y is -6 or smaller".

So the second answer you wrote is close, but you forgot the "or equal to" portion of the inequality sign.

See below for a visual example of what's going on.

Answer:

If its supposed to be simplify it will be -7 . If your finding the derivative it is 0.

Step-by-step explanation:

Answer:

The rea of walk way is 32 ft^2.

Step-by-step explanation:

width, w = 8 feet

length, L = 10 feet

width of walkway, d = 2 feet

length of outer, L' = 10 + 2 + 2 = 14 feet

Area of outer, A' = L' x w = 14 x 8 = 112 ft^2

Area of inner, A = L x w = 10 x 8 = 80 ft^2

The area of walkway = A' - A = 112 - 80 = 32 ft^2

The rea of walk way is 32 ft^2.

Answer:

Cost of 1 goggles = $20

Cost of 1 mask = 15

Step-by-step explanation:

Given:

Cost of 2 goggles and 1 mask = $55

Cost of 1 goggles and 2 mask = $50

Find:

Cost of each goggles and mask

Computation:

Assume;

Cost of 1 goggles = a

Cost of 1 mask = b

So,

2a + b = 55.....EQ1

a + 2b = 50.......EQ2

EQ1 x 2

4a + 2b = 110 ......EQ3

EQ3 - EQ2

3a = 60

a = 20

Cost of 1 goggles = $20

a + 2a = 50

20 + 2b = 50

2b = 30

b = 15

Cost of 1 mask = 15

.

Answer:

The answer is 12.

Step-by-step explanation:

Since one of the sides on the smaller polygon is two and on the other one is six that must mean the scale is multiply by 3 because 2x3=6. So 4 times 3 is 12.

So, w = 12

Answer:

I think C sorry if wrong

Step-by-step explanation:

Answer:

6

Step-by-step explanation:

again ?

7 = (3x - 4)/2

14 = 3x - 4

18 = 3x

x = 6

Answer:

R = [tex]\left[\begin{array}{ccc}-3&-2\\1&-3\\\end{array}\right][/tex]

Step-by-step explanation:

P - Q + R = I ( I is the identity matrix )

[tex]\left[\begin{array}{ccc}2&4\\3&5\\\end{array}\right][/tex] - [tex]\left[\begin{array}{ccc}-2&2\\4&1\\\end{array}\right][/tex] + R = [tex]\left[\begin{array}{ccc}1&0\\0&1\\\end{array}\right][/tex] ( subtract corresponding elements )

[tex]\left[\begin{array}{ccc}2-(-2)&4-2\\3-4&5-1\\\end{array}\right][/tex] + R = [tex]\left[\begin{array}{ccc}1&0\\0&1\\\end{array}\right][/tex]

[tex]\left[\begin{array}{ccc}4&2\\-1&4\\\end{array}\right][/tex] + R = [tex]\left[\begin{array}{ccc}1&0\\0&1\\\end{array}\right][/tex]

R = [tex]\left[\begin{array}{ccc}1&0\\0&1\\\end{array}\right][/tex] - [tex]\left[\begin{array}{ccc}4&2\\-1&4\\\end{array}\right][/tex] = [tex]\left[\begin{array}{ccc}-3&-2\\1&-3\\\end{array}\right][/tex]

Answer:

-6 and - 65

Step-by-step explanation:

X-12x-29, by completing the square we get (x-6)^2-65

7^2 + 6^2 = h^2

49 + 36 = h^2

85 = h^2

√85 = h

h = 9.21m

Answered by Gauthmath must click thanks and mark brainliest

Answer:

15

Step-by-step explanation:

first find f which is (8-3) × ( 1/4 × 7 + 5)

simplify

5 × (1/4 ×12)

5 × 3

15 is thw answer

Answer:

[tex]{ \sf{ - 2 {a}^{5} + 4 {a}^{4} + 5 {a}^{3} + \frac{2}{3}a }}[/tex]

Answer:

D

Step-by-step explanation:

A polynomial is in standard equation when the degree of the polynomial are in descending order.

Answer: 7/8

Cos2x has 3 formulas, Sinx is given in the question, we should use the formula with sinus. I guess that's the solution.

Answer:

m∠LMK = 50°

Step-by-step explanation:

This is an isosceles triangle. Isosceles triangles have two sides of equal length and two equal angles. This means ∠K and ∠M will have the same degrees.

The sum of the angles of a triangle is 180°. The following equation can be arranged and solved for the missing angles:

[tex]x+x+80=180\\2x+80=180\\2x=100\\x=50[/tex]

Therefore, m∠LMK = 50°.

Answer:

Step-by-step explanation: Scale [tex]\frac{130}{100} = \frac{13}{10}[/tex]

New dimensions [tex]16 * 1.3 --- 24*1.3 =20.8 cm * 31.2 cm[/tex]

Answer:

B) ΔABC and ΔA′B′C′ are congruent.

Step-by-step explanation:

Given

See attachment for [tex]\triangle ABC[/tex] and [tex]\triangle A'B'C'[/tex]

Required

Determine the relationship between both triangles

The single line on all sides of both triangles implies that the sides of the triangles are equal

i.e.

[tex]\triangle ABC \cong \triangle A'B'C'[/tex] --- sides

Similarly, the same mark on the three angles of both triangles means that the angles of the both triangles are equal

i.e.

[tex]\triangle ABC \cong \triangle A'B'C'[/tex] --- angles

Hence, both triangles are congruent

Answer:

B) ΔABC and ΔA′B′C′ are congruent.

Step-by-step explanation: