What is the answer to -2(a+3)

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

Natalia is making a pizza. The radius of the pizza is 25 inches. What is

aniked [119]

(b)(b)=25 cm2

b2=25 cm2

√(b2)=√(25 cm2)

b= 5 cm

Please note the square root of 25 was taken, as well as the square root of cm2.

Perimeter=4b

Perimeter=4(5 cm)

Perimeter=20 cm

Step:

A circle of radius = 12.5 or diameter = 25 or circumference = 78.54 cm has an area of: 4.909 × 10-8 square kilometers (km²) 0.04909 square meters (m²)

8 0

3 years ago

Can you guys help we with this question.

satela [25.4K]

Answer:

40

Step-by-step explanation:

(2x+1/(2x))^5 *(2x -1/(2x))^5

= ((2x)^2 -1/(2x)^2)^5 (a+b)*(a-b) =a2-b2

= (4x^2-1/4(x)^2)^5

now

x =4x^2. ,a = 1/4(x)^2 ,n =5

we have

general term = Cr *x^r *a^(n-r)

= Cr * (4x^2)^r * (1/4(x)^2)^(n-r)

= Cr *4^r * X^2r * 1/( 4^(n-r) *x^(2n-2r)

= Cr * 4^r/4^(n-r) * x^(2r)/x^(2n-2r)

= Cr * 4(2r-n) *x(4r-2n)

now for x^2

4r-2n = 2

4r -10=2

4r =12

r = 3

now for coeff

C(5,3) * 4^(2*3-5)

5!/(3!*(5-3)!) * 4

5*4/(2*1)*4

40

4 0

2 years ago

Read 2 more answers

Which is the graph for the equation y=-3x + 4?

Ivahew [28]

Answer:

its look like this

Step-by-step explanation:

3 0

3 years ago

Kimmi and her mom count 254 guests coming to the wedding. There are 9 tables at the wedding. How many guests sit at each table?

valkas [14]

Answer:

28 guests with 2 guests remaining

Step-by-step explanation:

254/9 = 28.2222222

so 28 remainder 2

hope this helps :) mark brainliest?

6 0

2 years ago