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2 years ago

A rectangular field with perimeter of 80m is to have an area of at least 380m² . Describe the possible lengths and of the field.

Mathematics

1 answer:

Kryger [21]2 years ago

6 0

$let \: x \: be \: the \: length \\ let \: y \: be \: the \: width$

$perimeter = 2x + 2y \\ area = xy$

$2x + 2y = 80 \\ xy = 380 \\ \\ x + y = 40 \\ xy = 380 \\ \\ x = 40 - y \\ (40 - y)y = 380$

$40y - y {}^{2} = 380 \\ y {}^{2} - 40y + 380 = 0 \\ y {}^{2} - 40y + 400 = 20 \\ (y - 20) {}^{2} = 20 \\ y - 20 =± \sqrt{20} \\ y_{1}=20-√20≈15.52786\\ y_{2}=20+√20≈24.4721$

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Need help with this question

Debora [2.8K]

Answer:

y=-1/2n+44

Step-by-step explanation:

The number of bean stalks, n, represents the x values

The yield, y, represents the y values

After reading the problem, we have two coordinates: (30,29) and (32, 28) Because this problem is asking for y=mn+b, we have to find the slope. How do we find the slope? We do so by using the slope formula y2-y1/x2-x1. Now let's input the coordinates into this formula.

1.) 28-29/32-30 = -1/2

Let's plug -1/2 into y=mn +b

2.) y=-1/2n+b

Now we have to find what b ( y intercept) equals. To find B, we plug a coordinate into x and y. Let's use (30,29)

3.) 29 = -1/2(30)+b

29 = -15 +b

44 = b

We have now found the linear relationship form for this problem: y=-1/2n +44

8 0

2 years ago

The graphs of f(x) =2/3x and g(x) =2/3x-2 are shown below.

4vir4ik [10]

Y1=2/3x , Y2=2/3x-2

those are the graph of the functions

3 0

2 years ago

How many milliequivalents of sodium chloride are contained with 3 L of normal saline?

AVprozaik [17]

Answer:

466mEq

Step-by-step explanation:

First, we need to know the concentration of NaCl in a normal saline solution, this is by definition 0.9%, meaning we have 0.9g of NaCl per 100ml of solution, we want to know how much NaCl we have in 3L (3000ml):

$3000ml*\frac{0.9g}{100ml}=27g=27000mg$

So, we have 27000mg in 3L of normal saline solution.

Now, acording to our milliequivalent (mEq) equation ( $mEq=\frac{mg}{pE}$ ) where pE is de molecular mass of NaCl divided by their charges, in this case 1:

$pE= \frac{23+35}{1}=\frac{58}{1} = 58$

Finally we substitute in the mEq formula:

$mEq=\frac{mg}{pE}=\frac{27000}{58}=466mEq$

I hope you find this information useful! Good luck!

4 0

2 years ago

Identify the lateral area and surface area of a regular triangular pyramid with base edge length 14 cm and slant height 15 cm

posledela

Answer:

D) L = 315 cm2 ; S = 399.9 cm2

Step-by-step explanation:

Lateral area;

3 × (½)(14)(15)

315 cm²

Surface area:

315 + (½)(14)(14)sin(60)

399.8704896 cm²

6 0

3 years ago

Read 2 more answers

Find the measure of each side of this triangles. Answer in exact form. Find x and y

Firdavs [7]

Answer:

x = 24/√3

4√3 = y

Step-by-step explanation:

We are given that this is a right triangle as well as two angles and a side.

Given that the angles in a triangle add up to 180 degrees, and a right angle is 90 degrees, we can say that the missing angle is equal to

(180-90-30) = 60 degrees

Next, given sohcahtoa, we can say that

sin(30) = opposite/hypotenuse = y/x

cos(30) = adjacent/hypotenuse = 12/x

tan(30) = opposite/adjacent = y/12

We want to only have one variable per equation so we can solve for the variable, so we can use

cos(30) = 12/x and tan(30) = y/12

Starting with cos(30) = 12/x, we can multiply both sides by x to remove the denominator to get

cos(30) * x = 12, and divide both sides by cos(30) to isolate the x and get

x = 12/cos(30). Next, cos(30) = √3/2, so we have

x = 12/(√3/2)

x = (12/1) / (√3/2)

x = (12/1) * (2/√3)

x = 24/√3

For y, we have

tan(30) = y/12

multiply both sides by 12 to isolate the y and remove the denominator

tan(30) * 12 = y

√3/3 * 12 = y

√3 * 4 = y

4√3 = y

4 0

3 years ago