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3 years ago

Please help with this inequality question!! I will give branliest to whoever answers!!

Mathematics

1 answer:

lapo4ka [179]3 years ago

5 0

Answer:

Step-by-step explanation:

the first one

the second one

the third one

the last one

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Tabitha decided to start saving pennies for a stretch of two months and initially started with 2 pennies. A table showing the nu

svetoff [14.1K]

Answer:

after week 7: 4374 pennies
486 pennies: after week 5

Step-by-step explanation:

The sequence values have a first term of 6 and a common ratio of 3, so can be described by the formula ...

an = 6·3^(n-1)

This can be rearranged to ...

an = 2·3^n

When n=7, the value is ...

a7 = 2·3^7 = 4374 . . . . pennies saved after 7 weeks

To find when there are 486 pennies saved, we can solve the equation ...

486 = 2·3^n

243 = 3^n

log(243) = n·log(3) . . . . . . . take the logarithm

log(243)/log(3) = n = 5 . . . . divide by the coefficient of n

Tabitha will have saved 486 pennies after 5 weeks.

7 0

3 years ago

30 seconds of 2.5 mins in percentage

WARRIOR [948]

Answer:

20%

Step-by-step explanation:

2.5 min =(60×2.5)sec=150 sec

30sec to 150sec=30×100/150=20%

7 0

3 years ago

Read 2 more answers

The radius of a cone is increasing at a constant rate of 7 meters per minute, and the volume is decreasing at a rate of 236 cubi

storchak [24]

Answer:

The rate of change of the height is 0.021 meters per minute

Step-by-step explanation:

From the formula

$V = \frac{1}{3}\pi r^{2}h$

Differentiate the equation with respect to time t, such that

$\frac{d}{dt} (V) = \frac{d}{dt} (\frac{1}{3}\pi r^{2}h)$

$\frac{dV}{dt} = \frac{1}{3}\pi \frac{d}{dt} (r^{2}h)$

To differentiate the product,

Let r² = u, so that

$\frac{dV}{dt} = \frac{1}{3}\pi \frac{d}{dt} (uh)$

Then, using product rule

$\frac{dV}{dt} = \frac{1}{3}\pi [u\frac{dh}{dt} + h\frac{du}{dt}]$

Since $u = r^{2}$

Then, $\frac{du}{dr} = 2r$

Using the Chain's rule

$\frac{du}{dt} = \frac{du}{dr} \times \frac{dr}{dt}$

∴ $\frac{dV}{dt} = \frac{1}{3}\pi [u\frac{dh}{dt} + h(\frac{du}{dr} \times \frac{dr}{dt})]$

Then,

$\frac{dV}{dt} = \frac{1}{3}\pi [r^{2} \frac{dh}{dt} + h(2r) \frac{dr}{dt}]$

Now,

From the question

$\frac{dr}{dt} = 7 m/min$

$\frac{dV}{dt} = 236 m^{3}/min$

At the instant when $r = 99 m$

and $V = 180 m^{3}$

We will determine the value of h, using

$V = \frac{1}{3}\pi r^{2}h$

$180 = \frac{1}{3}\pi (99)^{2}h$

$180 \times 3 = 9801\pi h$

$h =\frac{540}{9801\pi }$

$h =\frac{20}{363\pi }$

Now, Putting the parameters into the equation

$\frac{dV}{dt} = \frac{1}{3}\pi [r^{2} \frac{dh}{dt} + h(2r) \frac{dr}{dt}]$

$236 = \frac{1}{3}\pi [(99)^{2} \frac{dh}{dt} + (\frac{20}{363\pi }) (2(99)) (7)]$

$236 \times 3 = \pi [9801 \frac{dh}{dt} + (\frac{20}{363\pi }) 1386]$

$708 = 9801\pi \frac{dh}{dt} + \frac{27720}{363}$

$708 = 30790.75 \frac{dh}{dt} + 76.36$

$708 - 76.36 = 30790.75\frac{dh}{dt}$

$631.64 = 30790.75\frac{dh}{dt}$

$\frac{dh}{dt}= \frac{631.64}{30790.75}$

$\frac{dh}{dt} = 0.021 m/min$

Hence, the rate of change of the height is 0.021 meters per minute.

3 0

3 years ago

A square prism has square sides with area ++x squared , plus 8 x plus 16 and rectangular sides with area ++2 , x squared , plus

Irina18 [472]

Answer:

10x^2+76x+144

Step-by-step explanation: ayo if i helped thank me i hoped i did have a great day

3 0

3 years ago

∠A and ∠B are complementary angles.

iogann1982 [59]

Cos 52 = 0.6157

sin 42 = cos 48 = 2/3 (because 42 + 38 = 90 - complementary angles)

if tan 20,5 = 3/8 then tan 69.5 wil = 1 / 3/8 = 8/3

3 0

3 years ago