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3 years ago

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Mathematics

1 answer:

Sloan [31]3 years ago

6 0

Answer:

Sum of $\frac{7x}{x^2-4}$ and $\frac{2}{x+2}$ is $\mathbf{\frac{9x-4}{x^2-4}}$

Option B is correct answer.

Step-by-step explanation:

We need to find sum of $\frac{7x}{x^2-4}$ and $\frac{2}{x+2}$

Finding sum of $\frac{7}{x^2-4}$ and $\frac{2}{x+2}$ :

$\frac{7x}{x^2-4}+\frac{2}{x+2}$

We know that $x^2-4 =(x+2)(x-2)$

Replacing x^2-4

$\frac{7x}{(x+2)(x-2)}+\frac{2}{x+2}$

Now, taking LCM of (x+2)(x-2) and (x+2) we get (x+2)(x-2)

$=\frac{7x+2(x-2)}{(x+2)(x-2)}\\=\frac{7x+2x-4}{(x+2)(x-2)}\\=\frac{9x-4}{(x+2)(x-2)}\\=\frac{9x-4}{x^2-4}$

So, Sum of $\frac{7x}{x^2-4}$ and $\frac{2}{x+2}$ is $\mathbf{\frac{9x-4}{x^2-4}}$

Option B is correct answer.

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From base camp, a hiker walks 3.5 miles west and 1.5 miles north. Another hiker walks 2 miles east and 0.5 miles south. To the n

levacccp [35]

Answer:

The hikers are 5.9 miles apart.

Step-by-step explanation:

Let O represents the base camp,

Suppose after walking 3.5 miles west, first hiker's position is A, then after going 1.5 miles north from A his final position is B,

Similarly, after walking 2 miles east, second hiker's position is C then going towards 0.5 miles south his final position is D.

By making the diagram of this situation,

Let D' is the point in the line AB,

Such that, AD' = CD

In triangle BD'D,

BD' = AB + AD' = 1.5 + 0.5 = 2 miles,

DD' = AC = AO + OC = 3.5 + 2 = 5.5 miles,

By Pythagoras theorem,

$BD^2 = BD'^2 + DD'^2$

$BD = \sqrt{2^2 + 5.5^2}=\sqrt{4+30.25}=\sqrt{34.25}\approx 5.9$

Hence, the hikers are 5.9 miles apart.

8 0

3 years ago

Evaluate lim x=π/4(3x - tanx)

Karo-lina-s [1.5K]

Answer:

$\lim_{x \to\frac{\pi }{4} } (3x-tanx)$ = $3(\frac{\pi }{4} )$

Step-by-step explanation:

Explanation:-

Given that

$\lim_{x \to\frac{\pi }{4} } (3x-tanx)$

= $\lim_{x \to\frac{\pi }{4} } (3x) - \lim_{x \to\frac{\pi }{4} } tanx)$

= $3(\frac{\pi }{4} )+tan(\frac{\pi }{4} )$

= $3(\frac{\pi }{4} )+ 1 )$

= $3(\frac{\pi }{4} )$

5 0

3 years ago

The port of South Louisiana, located along 54 miles of the Mississippi River between New Orleans and Baton Rouge, is the largest

Ksenya-84 [330]

Answer:

a) 0.7287

b) 0.9663

c) 0.237

d) 3.65 tons of cargo per week or more that will require the port to extend its operating hours.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 4.5 million tons of cargo per week

Standard Deviation, σ = 0 .82 million tons

We are given that the distribution of number of tons of cargo handled per week is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

a) P( port handles less than 5 million tons of cargo per week)

P(x < 5)

$P( x < 5) = P( z < \displaystyle\frac{5 - 4.5}{0.82}) = P(z < 0.609)$

Calculation the value from standard normal z table, we have,

$P(x < 5) =0.7287= 72.87\%$

b) P( port handles 3 or more million tons of cargo per week)

$P(x \geq 3) = P(z \geq \displaystyle\frac{3-4.5}{0.82}) = P(z \geq −1.82926)\\\\P( z \geq −1.82926) = 1 - P(z < -1.829)$

Calculating the value from the standard normal table we have,

$1 - 0.0337 = 0.9663 = 96.63\%\\P( x \geq 3) = 96.63\%$

c)P( port handles between 3 million and 4 million tons of cargo per week)

$P(3 \leq x \leq 4) = P(\displaystyle\frac{3 - 4.5}{0.82} \leq z \leq \displaystyle\frac{4-4.5}{0.82}) = P(-1.829 \leq z \leq -0.609)\\\\= P(z \leq -0.609) - P(z < -1.829)\\= 0.271-0.034 = 0.237= 23.7\%$

$P(3 \leq x \leq 4) = 23.7\%$

d) P(X=x) = 0.85

We have to find the value of x such that the probability is 0.85.

P(X > x)

$P( X > x) = P( z > \displaystyle\frac{x - 4.5}{0.82})=0.85$

$= 1 -P( z \leq \displaystyle\frac{x - 4.5}{0.82})=0.85$

$=P( z \leq \displaystyle\frac{x - 4.5}{0.82})=0.15$

Calculation the value from standard normal z table, we have,

$P( z \leq -1.036) = 0.15$

$\displaystyle\frac{x - 4.5}{0.82} = -1.036\\x = 3.65$

Thus, 3.65 tons of cargo per week or more that will require the port to extend its operating hours.

8 0

3 years ago

Find f¹(x) for the function f(x) = -4. 2 f¹(x) = [?]x + [ ]

g100num [7]

Answer:

${f}^{ - 1}(x) = 2x + 8$

Step-by-step explanation:

$f(x) = \frac{x}{2} - 4 \\ \\ y = \frac{x}{2} - 4 \\ \\ y = \frac{x - 8}{2} \\ \\ x = 2y + 8 \\ \\ {f}^{ - 1} (x) = 2x + 8$

4 0

2 years ago

I need help on this question

Irina18 [472]

To find the surface area of the figure , we need to add the surface area of all the faces

So the surface area of figure = Area of two lateral rectangular faces + Area of two triangular faces + area of base

hence

Surface Area of figure = 2(10*15) + 2( 1/2 * 8 * 12) + (12*15)

= 300 + 96 + 180

= 576 square feet

So correct option is the last one

7 0

3 years ago