Find a formula for the nth term

pantera1 [17]

First combine like terms:
6n-2n = 4n
7n-2=4n
subtract 7n from both sides
7n-2=4n
-7n -7n
-2=-3n
divide -2 on both sides.
n=1.5

7 0

3 years ago

The width of a container is 5 feet less than its height. Its length is 1 foot longer than its height. The volume of the containe

juin [17]

The height of container is 8 feet

Solution:

Let "w" be the width of container

Let "l" be the length of container

Let "h" be the height of container

The width of a container is 5 feet less than its height

Therefore,

width = height - 5

w = h - 5 ------ eqn 1

Its length is 1 foot longer than its height

length = 1 + height

l = 1 + h ---------- eqn 2

The volume of container is given as:

$v = length \times width \times height$

Given that volume of the container is 216 cubic feet

$216 = l \times w \times h$

Substitute eqn 1 and eqn 2 in above formula

$216 = (1 + h) \times (h-5) \times h\\\\216 = (h+h^2)(h-5)\\\\216 = h^2-5h+h^3-5h^2\\\\216 = h^3-4h^2-5h\\\\h^3-4h^2-5h-216 = 0$

Solve by factoring

$(h-8)(h^2+4h+27) = 0$

Use the zero factor principle

If ab = 0 then a = 0 or b = 0 ( or both a = 0 and b = 0)

Therefore,

$h - 8 = 0\\\\h = 8$

Also,

$h^2+4h+27 = 0$

Solve by quadratic equation formula

$\text {For a quadratic equation } a x^{2}+b x+c=0, \text { where } a \neq 0\\\\x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}$

$\mathrm{For\:} a=1,\:b=4,\:c=27:\quad h=\frac{-4\pm \sqrt{4^2-4\cdot \:1\cdot \:27}}{2\cdot \:1}$

$h = \frac{-4+\sqrt{4^2-4\cdot \:1\cdot \:27}}{2}=\frac{-4+\sqrt{92}i}{2}$

Therefore, on solving we get,

$h=-2+\sqrt{23}i,\:h=-2-\sqrt{23}i$

Thus solutions of "h" are:

h = 8

$h=-2+\sqrt{23}i,\:h=-2-\sqrt{23}i$

"h" cannot be a imaginary value

Thus the solution is h = 8

Thus the height of container is 8 feet

8 0

3 years ago

An oil tank is leaking into a lake at a rate of 0.1 m3/day. The oil slick forms a semicircular disk whose center is at the leak

gregori [183]

Answer:

17.9 m/s

Step-by-step explanation:

Volume of the slick = 0.5 x π r² h--------------------------------- (1)

Where r = radius of slick

h = thickness of slick, 10⁻⁶m

If 0.5m³ of oil leaked, then the radius of the semicircular slick can be calculated from equation (1)

V = 0.5 x π r² h

0.5= 0.5 x π x r² x 10⁻⁶

r² = 10⁶/ π

r = 10³/√π

dV/dt = πrh dr/dt + 0.5π r² dh/dt----------------------------------- (2)

Asumming the film thickness is constant , equation (2) becomes

dV/dt = πrh dr/dt-------------------------------- (3)

dV/dt = 0.1m³/day

r= 10³/√π

dr/dt= rate of expansion of the slick

Substituting into (3);

0.1 = π x 10³/√π x 10⁻⁶ x dr/dt

dr/dt = 0.1 x 10⁶/ ( π x 10³/√π)

= 17.9479 m/s

≅ 17.9 m/s

8 0

3 years ago

Felipe, Pedro y Miguel son fanáticos del cine. Felipe asiste cada 3 días; Pedro cada 6 días y Miguel cada 5 días. Los tres van j

lilavasa [31]

Answer:

Opción C, 30 días.

Step-by-step explanation:

Sabemos que:

Felipe asiste al cine cada 3 días

Miguel asiste cada 5 días.

Pedro asiste cada 6 días.

Los tres van juntos un día, ¿dentro de cuántos días irán otra vez juntos?

Los 3 volverán a ir juntos luego de N días, tal que N es el menor múltiplo común de 3, 5 y 6.

Como 6 es múltiplo de 3, podemos ignorar al 3, y solo considerar al menor múltiplo en común de 5 y 6.

Además, como podemos reescribir estos números como un producto de números primos, así obtenemos:

6 = 2*3

5 = 5*1

Estos números no comparten factores entre ellos, por lo que el menor múltiplo entre 5 y 6 es simplemente 5*6 = 30

Entonces podemos concluir que N = 30

Felipe, Pedro y Miguel irán juntos al cine nuevamente dentro de 30 días.

La opción correcta es C.

5 0

3 years ago

Please help dont answer if u dont know it

jolli1 [7]

Answer:

D

Step-by-step explanation:

using the formula y = mx + b we can plug in the m and the b, getting

y = -5x - 9

7 0

3 years ago

Read 2 more answers