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rosijanka [135]

3 years ago

11

If the first and the last terms of an arithmetic series are 10 and 62, show that the sum of the series varies directly as the nu

mber of terms.

1 answer:

Nitella [24]3 years ago

6 0

Answer:

10+^@=72_^) + the series

Step-by-step explanation:

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You decide to enter in a rowing competition. To train, you go to the boat house and begin rolling down stream. You row for the s

fredd [130]

Answer:

Time spent rowing down stream $=100\ seconds$

Speed of boat in still water $=14\ ms^{-1}$

Step-by-step explanation:

Let speed of boat in still water be $= x\ ms^{-1}$

Speed of current $= 10\ ms^{-1}$

Speed of boat down stream = $\textrm{Speed of boat in still water +Speed of current}= (x+10)\ ms^{-1}$

Distance rowed down stream = 2400 m

Time spent rowing down stream = $\frac{Distance}{Speed}=\frac{2400}{x+10}\ s$ = $\frac{Distance}{Speed}=\frac{2400}{x+10}\ s$

Speed of boat up stream = $\textrm{Speed of boat in still water -Speed of current}= (x-10)\ ms^{-1}$

Distance rowed up stream = $\frac{1}{6} \textrm{ of distance rowed downstream}=\frac{1}{6}\times 2400 = 400\ m$

Time spent rowing up stream = $\frac{Distance}{Speed}=\frac{400}{x-10}\ s$

We know that,

$\textrm{Time spent rowing down stream =Time spent rowing up stream}$

So,

$\frac{2400}{x+10}=\frac{400}{x-10}$

Cross multiplying

$2400(x-10)=400(x+10)$

Dividing both sides by $400$

$\frac{2400(x-10)}{400}=\frac{400(x+10)}{400}$

$6(x-10)=x+10$

$6x-60=x+10$

Adding 60 to both sides.

$6x-60+60=x+10+60$

$6x=x+70$

Subtracting both sides by $x$

$6x-x=x+70-x$

$5x=70$

Dividing both sides by 5.

$\frac{5x}{5}=\frac{70}{5}$

∴ $x=14$

Speed of boat in still water $=14\ ms^-1$

Time spent rowing down stream = $\frac{2400}{14+10}=\frac{2400}{24}=100\ s$

3 0

3 years ago

Write an expression to<br> represent the perimeter of<br> the rectangle:<br> 3* +10<br> * +5

Schach [20]

Answer:

the perimeter is 18

Step-by-step explanation:

3 0

3 years ago

The compound inequality 8.00 ≤ x < 9.50 represents all values, x, for which college students are paid hourly as teacher assis

Orlov [11]

Answer: x≥ 8.00 and x < 9.50 is the correct option.

Step-by-step explanation:

Since, given expression 8.00 ≤ x < 9.50

Where x is the value for which college students are paid hourly as teacher assistants.

so, x is greater than or equal to 8.00

Therefore, $x\geq 8.00$

And, x is less than 9.50

Therefore, x < 9.50

On combining both expression we get, $x\geq 8.00$ and $x < 9.50$ .

Thus, Third Option is correct.

3 0

3 years ago

Read 2 more answers

Determine whether or not the two triangles are congruent. If they are state by what postulate.

avanturin [10]

Congruent
SSS (because of Pythagoras)

8 0

3 years ago

Write the value represented on the number line next to the letter

miss Akunina [59]

Okay, I understand. You found the correct answer. I won't get points. Sniffle.Sniffle.

8 0

3 years ago