2 2/3×2 2/5 please answer quickly

The pool dimensions that will minimize the cost of construction are length of square bottom = 20 ft and height of pool = 5 ft

Let l be the length of side of the square bottom of the pool and h be the height of the pool.

Its volume V = l²h

Now, the total surface area of the pool equal the area of its sides plus the area of its base.

The area of its 4 sides is 4lh.

Since the cost of the side of the pool is $80 per square foot, the total cost for the sides of the pool is C = $80 × 4lh = $ 320lh

Also, The area of its square bottom is l².

Since the cost of the side of the pool is $40 per square foot, the total cost for the square bottom of the pool is C' = $40 × l² = $ 40l²

So, the total cost of the pool is C" = C + C' = 320lh + 40l²

C" = 320lh + 40l²

Since the volume equals 2000 ft³, V = l²h

2000 = l²h

h = 2000/l²

Substituting h into C", we have

C" = 320lh + 40l²

C" = 320l × 2000/l² + 40l²

C" = 640000/l + 40l²

To find the value of l which makes C" minimum, we differentiate C" with respect to l and equate it to zero.

So, dC"/dl = d(640000/l + 40l²)/dl

dC"/dl = d(640000/l)/dl + d(40l²)/dl

dC"/dl = -640000/l² + 80l

Equating dC"/dl to zero, we have

-640000/l² + 80l = 0

-640000/l² = -80l

Cross-multiplying, we have

640000 = 80l³

Dividing through by 80, we have

l³ = 640000/80

l³ = 8000

Taking cube root of both sides, we have

l = ∛8000

l = 20 ft

We differentiate C" twice to determine if this value of l gives a minimum for C".

So, d²C"/dl² = d(-640000/l² + 80l)/dl

d²C"/dl² = d(-640000/l²)/dl + d(80l)/dl

d²C"/dl² = 640000/l³ + 80

Substituting l = 20, we have

d²C"/dl² = 640000/l³ + 80

d²C"/dl² = 640000/20³ + 80

d²C"/dl² = 640000/8000 + 80

d²C"/dl² = 80 + 80

d²C"/dl² = 160 > 0

Since d²C"/dl² = 160 > 0. So, l = 20 ft gives a minimum for C".

Since h = 2000/l²

Substituting l = 20 into the equation, we have

h = 2000/l²

h = 2000/20²

h = 2000/400

h = 5 ft

So, the pool dimensions that will minimize the cost of construction are length of square bottom = 20 ft and height of pool = 5 ft

Learn more about dimensions of a pool here:

https://brainly.com/question/22112169

Answer:

I only know the second one sooorrry

if you say its classification so that type of traingle is obtuse triangle

Step-by-step explanation:

Answer:

8000

Step-by-step explanation:

Answer:

y=4

Step-by-step explanation:

84=30y-9y, first you collect like terms.

84=21y, swap the sides

21y=84, devide both sides and you get y =4

Step-by-step explanation:

as you can see, the distance between 2 points can always be seen as the Hypotenuse or baseline of a right-angled triangle created by the differences of the x and y coordinates of both points.

the drawn triangle is nothing else than that.

to calculate the length of a side in such a triangle we need to use Pythagoras :

c² = a² + b²

c is the Hypotenuse of baseline of the triangle and is opposite of the 90 degree angle.

a and b are the legs of the triangle "enclosing" the 90 degree angle.

so, we have

AB² = AC² + BC²

AC and BC we know : the coordinate differences in x and y directions.

AC = (4, 5) to (4, 2). as the x coordinates are the same, the difference is just the difference in the y coordinates : 5-2 = 3.

BC = (1, 2) to (4, 2). as the y coordinates are the same, the difference is just the difference in the x coordinates : 5-1 = 3.

AB² = 3² + 3² = 9 + 9 = 18

AB = sqrt(18)

FYI : sqrt(18) = sqrt(9×2) = 3×sqrt(2)

Answer:

Step-by-step explanation:

Given:

Required equations:

Solve by elimination, multiply the first equation by 10 and subtract from the second equation:

Find p:

Let's take the given as,

→ q = quarters (25)

→ d = dimes (10)

→ 1320 will be the amount

→ q + d = 72

→ 25q + 10d = 1320

Now we can solve for q,

→ (25q - 10q) + (10d - 10d) = 1320 - (10 × 72)

→ 15q = 1320 - 720

→ 15q = 600

→ q = 600/15

→ [ q = 40 ]

From this equation,

→ q + d = 72

We can solve for the d,

→ 40 + d = 72

→ d = 72 - 40

→ [ d = 32 ]

There are 40 quarters & 32 dimes.

[tex]\left \{ {{-6y = -12} \atop {3x + 2y = -2}} \right. <=> \left \{ {{y = 2} \atop {3x + 2y = -2}} \right. <=> \left \{ {{y=2} \atop {3x + 2*2 = -2}} \right. <=> \left \{ {{y=2} \atop {3x = -6}} \right. <=> \left \{ {{y=2} \atop {x=-2}} \right.\\ => \left \{ {{y=2} \atop {x=-2}} \right.[/tex]

Answer:

-10

Step-by-step explanation:

The rate of change is also known as the slope of the function thus the slope will be -600.

A slope is a tangent or angle at a point and a slope is the intensity of inclination of any geometrical lines.

Slope = Tanx where x will be the angle from the positive x-axis at that point.

The slope is also calculated by differentiation for example slope of y = sinx will be y' = cosx.

As per the given,

Bacteria are dying at a constant rate of $600$ an hour.

The rate of change = -600/hour

Slope = y/x = number of bacteria change/time taken

If the graph is a straight line then it will remain constant.

Slope = -600

Hence "The rate of change is also known as the slope of the function thus the slope will be -600".

To learn more about slopes,

https://brainly.com/question/3605446

#SPJ2

15% of $18 is $2.70...........

Answer:

x is -3

Step-by-step explanation:

Answer:

397

Step-by-step explanation:

1. To evaluate this expression, we plug in the value of x and simplify.

Therefore, the answer is 397.

Answer:

it looks like 60

Step-by-step explanation:

Answer:

6°

Step-by-step explanation:

The angles in a triangle always add up to 180°. Let’s call the third angle x. That means that:

154 + 20 + x = 180 ->

174 + x = 180 ->

x = 180 - 174 ->

x = 6°

Hope that help! :)

Answer:

[tex]y=\frac{4}{3}x-.333[/tex]

Step-by-step explanation:

Answer:

502

Step-by-step explanation

108 has the numbers 0, 1, and 8 which added together totals 9

603 has the numbers 0, 3, and 6 which added together totals 9

360 has the numbers 0, 3, and 6 which added together totals 9

502 has the numbers 0, 2, and 5 which equal 7

502 is the odd one out

Answer:

[tex]T(2,4) and U(11,13)[/tex]

Step-by-step explanation:

Answer:

The answer is 2.70

Step-by-step explanation:

18+2.70= 20.70

20.70-2.70=18

Answer:

The code is 8415

Step-by-step explanation:

I can't give a very good answer as I don't know what resources are available to you, but this is what I managed to find with a ti-84 calculator.

[tex]y=-31.24+1.34x[/tex]

If you want a better step-by-step, tell me what's in that 'open statistics calculator' option and I'll see what I can figure out.

edit: missed that second part of the question

Using this equation to calculate a test grade with a homework grade of 90:

[tex]y=-31.24+1.34(90)=89[/tex]

Answer:

2 friends

Step-by-step explanation:

Answer:

3 1/2

Step-by-step explanation:

Answer:

1

Step-by-step explanation:

/14-15/

/-1/

1(because absolute value of any real number is always positive and for zero itself zero)

Answer:

It is congruent doe to the angle side angle congruence thereom AKA ASA

Step-by-step explanation:

That means there are two angles and one side in between. A pair of triangles  that follow this rule has an angle that is congruent to one angle. Then a side that has a tick mark after the angle must match another. Then the last angle has to match another angle ( and it can't be the same angle as before).  Usually the first pair angles have 1 semicircle and the second pair has 2 semicircles.

Answer:

2,400

Step-by-step explanation:

Can I please have brainliest?? thanks!! have an awesome day and good luck with your math :)

Answer:

2,400

Step-by-step explanation:

Answer:

-1/2

Step-by-step explanation:

Answer:

i dont know sry....i ned points..

Multiply the original dimensions by the scale:

8 x 3.5 = 28

6 x 3.5 = 21

New dimensions:  length = 28, width = 21

Evaluate

[tex] \sf \longmapsto \: y + h[/tex]

When

Let's start.

[tex] \sf \longmapsto \: y + h[/tex]

[tex] \sf \longmapsto6 +0[/tex]

[tex] \sf \longmapsto6[/tex]

Answer:

10.5 degrees Celsius

Step-by-step explanation:

Answer: 13.5

Step-by-step explanation:

This is because 3x4.5=13.5

Answer:

8

Step-by-step explanation:

it just makes sense, 5=10, therefore 4=8.