All categories

3 years ago

Solve for y.8^3-3y=256^4y

1 answer:

3 0

$8^{3-3y}=256^{4y}\\\\(2^3)^{3-3y}=(2^8)^{4y}\\\\2^{3(3-3y)}=2^{8\cdot4y}\\\\2^{9-9y}=2^{32y}\iff9-9y=32y\\\\-9y-32y=-9\\-41y=-9\ \ \ \ /:(-41)\\\\y=\frac{9}{41}$

You might be interested in

Describe how to write 3x+2y=12 in function notation. Assume that y represents the dependant variable.

kotegsom [21]

Im not so sure but, 3x2=6; 2x3=6; 6+6=12

5 0

3 years ago

if the area of a triangular base prism is 11 cm² and the height of the prism is 12 cm, what is the volume of the prism?

Natasha2012 [34]

Answer:

132 cm²

Step-by-step explanation:

Your welcome

7 0

2 years ago

Newton's law of cooling is:

Mnenie [13.5K]

Answer:

$t = \frac{ln(\frac{21}{59})}{-0.15}=6.887 hr$

So it would takes approximately 6.9 hours to reach 32 F.

Step-by-step explanation:

For this case we have the following differential equationÑ

$\frac{du}{dt}= -k (u-T)$

We can reorder the expression like this:

$\frac{du}{u-T} = -k dt$

We can use the substitution $w = u-T$ and $dw =du$ so then we have:

$\frac{dw}{w} =-k dt$

IF we integrate both sides we got:

$ln |w| = -kt +C$

If we apply exponential in both sides we got:

$w = e^{-kt} *e^c$

And if we replace w = u-T we got:

$u(t)= T + C_1 e^{-kt}$

We can also express the solution in the following terms:

$u(t) = (T_i -T_{amb}) e^{kt} +T_{amb}$

For this case we know that $k =-0.15 hr$ since w ehave a cooloing, $T_{i}= 70 F, T_{amb}=11F$ , we have this model:

$u(t) = (70-11) e^{-0.15t} +11$

And if we want that the temperature would be 32F we can solve for t like this:

$32 = 59 e^{-0.15 t} +11$

$21=59 e^{-0.15 t}$

$\frac{21}{59} = e^{-0.15 t}$

If we apply natural logs on both sides we got:

$ln (\frac{21}{59}) =-0.15 t$

$t = \frac{ln(\frac{21}{59})}{-0.15}=6.887 hr$

So it would takes approximately 6.9 hours to reach 32 F.

7 0

4 years ago

Please help i need it

vichka [17]

Answer:

x = 100

Step-by-step explanation:

The area of the left square is 3600

A =s^2

3600 = s^2

Taking the square root of each side

60 =s

The area of the right square is 1600

A =s^2

1600 = s^2

Taking the square root of each side

40 =s

Adding the lengths

60+40 =x

100 =x

3 0

3 years ago

Pls help will give brainliest and 5 star

jeka94

Answer:

The answers are as follows:

5. c

6. b

7. not sure, sorry

8. b

Step-by-step explanation:

8 0

3 years ago