All categories

3 years ago

Help please !!!!!!!!!!!!!!!

Mathematics

2 answers:

WITCHER [35]3 years ago

6 0

Answer:

I hope this helps!

FrozenT [24]3 years ago

3 0

Answer:

Step-by-step explanation:

Been a while since i’ve done this but I’ pretty sure since A starts on 2 and goes back 7 (into the negatives for minus 7) it would be A.

You might be interested in

A culture started with 5000 bacteria. after 7 hours, it grew to 6500 bacteria. predict how many bacteria will be present after 1

spin [16.1K]

6500=7x+5000

6500-5000=7x+5000-5000

1500=7x

1500/7≈214

x≈214

y=19·214+5000

y=9066

answer=9066 bacteria

4 0

3 years ago

Is 8m-4m+4m and 8m equivalent?

marta [7]

Answer:

Step-by-step explanation:

good luck

follow me for more

8 0

3 years ago

A comet is about 7.63 × 103 miles from Earth. Write this number in standard form.

Simora [160]

Answer:

7630

Step-by-step explanation:

We have that the distance of a comet from Earth is about 7.63*10³ .

This number is given in scientific notation.

We want to write this number in standard form.

Since we are multiplying by a power of 10, we move forward three times.

Therefore in standard form:

$7.63 \times {10}^{3} = 7630$

3 0

3 years ago

A rumor spreads through a small town. Let y ( t ) be the fraction of the population that has heard the rumor at time t and assum

Ivan

Answer:

Differential equation

$\frac{dy}{dt} =ky(1-y)$

Solution

$y=\frac{1}{1+4e^{-0.327t}}$

Value of constant k=0.327 days^(-1)

The rumor reaches 80% at 8.48 days.

Step-by-step explanation:

We know

y(t): proportion of people that heard the rumor

y'(t)=ky(1-y), rate of spread of the rumor

Differential equation

$\frac{dy}{dt} =ky(1-y)$

Solving the differential equation

$\frac{dy}{y(1-y)}=k\cdot dt \\\\\int \frac{dx}{y(1-y)} =k \int dt \\\\-ln(1-\frac{1}{y} )+C_0=kt\\\\1-\frac{1}{y} =Ce^{-kt}\\\\\frac{1}{y} =1-Ce^{-kt}\\\\y=\frac{1}{1-Ce^{-kt}}$

Initial conditions:

$y(0)=0.2\\y(3)=0.4\\\\y(0)=0.2=\frac{1}{1-Ce^0}\\\\1-C=1/0.2\\\\C=1-1/0.2= -4\\\\\\y(3)=0.4=\frac{1}{1+4e^{-3k}} \\\\1+4e^{-3k}=1/0.4\\\\e^{-3k}=(2.5-1)/4=0.375\\\\k=ln(0.375)/(-3)=0.327\\\\\\y=\frac{1}{1+4e^{-0.327t}}$