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3 years ago

6

HELP I WILL GIVE BRAINLIEST!!

1 answer:

Reika [66]3 years ago

7 0

Answer:

x=40

Step-by-step explanation:

2x+7+x-10+63=180

3x=120

x=40

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Pam has 90 m of fencing to enclose an area in a petting zoo with two dividers to separate three types of young animals. The thre

andrew-mc [135]

Answer:

The area function is

$A=\frac{135}{2}x-\frac{9}{2}x^2$ .

The domain and range of A is $(0,15m)$ and $(0, 253.125 m^2]$ .

Step-by-step explanation:

The given length of fencing is $90 m$ .

Let the length and width of each pen be $x$ and $y$ respectively as shown in the figure.

As there are 3 pens, so, the total area,

$A= 3 xy \;\cdots (i)$

From the figure the total length of fencing is $6x+4y$ .

Here, for a significant area for the animals, $x>0$ as well as $y>0$ as $x$ and $y$ are the sides of ben.

From the given value:

$6x+4y=90\;\cdots (ii)$

$\Rightarrow y=\frac {45}{2}-\frac{3x}{2}$

Now, from equation (i)

$A=3x\left(\frac {45}{2}-\frac{3x}{2}\right)$

$\Rightarrow A=\frac{135}{2}x-\frac{9}{2}x^2\;\cdots (iii)$

This is the required area function in the terms of variable $x$ .

For the domain of area function, from equation (ii)

$x=15-\frac{2y}{3}$

$\Rightarrow x$ [as y>0]

So, the domain of area function is $(0,15m)$ .

For the range of area function:

As $x \rightarrow 0$ or $y\rightarrow 0$ , then $A\rightarrow 0$ [from equation (i)]

$\Rightarrow A>0$

Now, differentiate the area function with respect to $x$ .

$\frac {dA}{dx}=\frac{135}{2}-9x$

Equate $\frac {dA}{dx}$ to zero to get the extremum point.

$\frac {dA}{dx}=0$

$\Rightarrow \frac{135}{2}-9x=0$

$\Rightarrow x=\frac{15}{2}$

Check this point by double differentiation

$\frac {d^2A}{dx^2}=-9$

As, $\frac {d^2A}{dx^2}$ , so, point $x=\frac{15}{2}$ is corresponding to maxima.

Put this value back to equation (iii) to get the maximum value of area function. We have

$A=\frac{135}{2}\times \frac {15}{2}-\frac{9}{2}\times \left(\frac {15}{2}\right)^2$

$\Rightarrow A=253.125 m^2$

Hence, the range of area function is $(0, 253.125 m^2]$ .

4 0

3 years ago

Factorise the following.

spin [16.1K]

Answer:

x²(9x– 11)(9x + 11)

Step-by-step explanation:

81x⁴ – 121x²

The expression can be factorised as follow:

81x⁴ – 121x²

x² is common to both term. Thus:

81x⁴ – 121x² = x²(81x² – 121)

Recall:

81 = 9²

121 = 11²

Therefore,

x²(81x² – 121) = x²(9²x² – 11²)

= x²[(9x)² – 11²]

Difference of two squares

x²(9x– 11)(9x + 11)

Therefore,

81x⁴ – 121x² = x²(9x– 11)(9x + 11)

3 0

2 years ago

9x + 26 + 7x - 17 = 2x + (-3x) + 5x

slega [8]

9x + 26 + 7x - 17 = 2x + (-3x) + 5x =
16x + 9 = 2x - 3x + 5x =
16x + 9 = 4x
9 = 4x - 16x
9 = - 12x
-9/12 = x
- 3/4 = x

4 0

2 years ago

A and B are complementary angles. If A = (x – 23)° and m

Lana71 [14]

Answer:

∠ B = 85°

Step-by-step explanation:

Complementary angles sum to 90° , then

x - 23 + 2x + 29 = 90 , that is

3x + 6 = 90 ( subtract 6 from both sides )

3x = 84 ( divide both sides by 3 )

x = 28

Then

∠ B = 2x + 29 = 2(28) + 29 = 56 + 29 = 85°

5 0

2 years ago

An above ground swimming pool is leaking after 1 and 1/2 hours the pool has leaked 7/8 of a gallon of water how many gallons of

Aleksandr [31]

Answer:

In 1 hour the amount of water leaking from pool = $\frac{7}{12}$ gallon of water

Step-by-step explanation:

Given as :

The amount of Leaking of water from the pool = $\frac{7}{8}$ gallon

The time taken fro leaking $\frac{7}{8}$ gallon of water = 1 $\frac{1}{2}$ gallon hour

Or The time taken fro leaking $\frac{7}{8}$ gallon of water = $\frac{3}{2}$ hour

∵ $\frac{3}{2}$ hour takes for leaking $\frac{7}{8}$ gallon of water

∴ In 1 hour the amount of water leaking from pool = $\frac{7}{8}\setminus \frac{3}{2}$

Or, In 1 hour the amount of water leaking from pool = $\frac{7}{12}$ gallon of water Answer

8 0

2 years ago