I need help please and thank you

Un escalador sube 225m de altura. El asenso lo hizo en 3 etapas. En la primera subio un quinto en la, en la tercera un cuarto. ¿

kiruha [24]

Answer:

Segunda etapa= 123.75 metros

Step-by-step explanation:

Altura total= 225 metros

<u>En la primera estapa subió el 20% (un quinto):</u>

Primera etapa= 225*0.2= 45 metros

<u>En la tercera etapa subió 25% (un cuarto):</u>

Tercera etapa= 225*0.250 56.25 metros

Ahora debemos determinar cuánto subió en la segunda etapa:

Segunda etapa= altura total - total subido

Segunda etapa= 225 - (45 + 56.25)

Segunda etapa= 123.75 metros

6 0

3 years ago

A box with a square base and an open top is being constructed out of A cm2 of material. If the volume of the box is to be maximi

viktelen [127]

Answer:

Side length = $\sqrt{\frac{A}{3} }$ cm , Height = $\frac{1}{2} \sqrt{\frac{A}{3} }$ cm , Volume = $\frac{A\sqrt{A}}{6\sqrt{3} }$ cm³

Step-by-step explanation:

Assume

Side length of base = x

Height of box = y

total material required to construct box = A ( given in question)

So it can be written as

A = x² + 4xy

4xy = A - x²

$y = \frac{A - x^{2} }{4x}$

Volume of box = Area x height

V = x² ₓ y

V = x² ₓ ( $\frac{A - x^{2} }{4x}$ )

V = $\frac{Ax - x^{3} }{4}$

To find max volume put V' = 0

So taking derivative equation becomes

$\frac{A - 3 x^{2} }{4} = 0$

A = 3 $x^{2}$

$x^{2}$ = $\frac{A}{3}$

x = $\sqrt{\frac{A}{3\\} }$

put value of x in equation 1

y = $\frac{A - \frac{A}{3} }{4\sqrt{\frac{A}{3} } }$

y = $\frac{2 \sqrt{\frac{A}{3} } }{4 \sqrt{\frac{A}{3} } }$

y = $\frac{1}{2} \sqrt{\frac{A}{3} }$

So the volume will be

V = $x^{2}$ × y

Put values of x and y from equation 2 & 3

V = $\frac{A}{3} (\frac{1}{2} \sqrt{\frac{A}{3} } )$

V = $\frac{A\sqrt{A}}{6\sqrt{3} }$

8 0

3 years ago

Are the lines below parallel, perpendicular, or neither?

levacccp [35]

Answer:

<h2>Neither </h2><h2></h2>

2y = 3x - 4

y = 2/3x - 3

Step-by-step explanation:

Parallel means the lines never cross. These two lines cross. Perpendicular means they cross and form a 90° angle.

5 0

3 years ago

Read 2 more answers

A closed box with a square base is to have a volume of 85. 75 cm^3. the material for the top and bottom of the box costs $3.00

tiny-mole [99]

We can create two equations here:

(1) Volume = area of square * height of box

85.75 = s^2 h

(2) Cost = 3 * area of square + 1.5 * area of side box

C = 3 s^2 + 1.5 s h

From (1), we get:

h = 85.75 / s^2

Combining this with (2):

C = 3 s^2 + 1.5 s (85.75 / s^2)

C = 3 s^2 + 128.625 s-

Taking the 1st derivative and equating dC/ds = 0:

dC/ds = 6s – 128.625 / s^2 = 0

Multiply all by s^2:

6s^3 – 128.625 = 0

6s^3 = 128.625

s = 2.78 cm

So h is:

h = 85.75 / s^2 = 85.75 / (2.78)^2

h = 11.10 cm

So the dimensions are 2.78 cm x 2.78 cm x 11.10 cm

The total cost now is:

C = 3 (2.78)^2 + 1.5 (2.78) (11.10)

C = $69.47

8 0

3 years ago

A family has two cars. The first car has a fuel efficiency of 40 miles per gallon of gas and the second has a fuel efficiency of

kozerog [31]

Answer:

Step-by-step explanation:

Let x = gallons consumed by car 1

Let y = gallons consumed by car 2

We set up our equations:

35x+40y = 1850 eq1

x+y = 50 eq2

Substituting eq 2 into eq 1,

35x+40(50-x) = 1850

35x+2000-40x = 1850

-5x+2000 = 1850

-5x = -150

x = 30

Substitute value of x into eq 2.

x+y = 50

30+y = 50

y = 20

Car 1 consumes 30 gallons of gas.

Car 2 consumes 20 gallons of gas.

6 0

3 years ago