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4 years ago

Seven more than one half a number as an equation

Mathematics

1 answer:

romanna [79]4 years ago

5 0

Answer:

1/2x+7

Step-by-step explanation:

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I'm not sure where to begin or end I just need the answers nothing needs to be worked out

Georgia [21]

For the top or bottom?

7 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 assume t

sladkih [1.3K]

Answer:

The answer is shown below

Step-by-step explanation:

Let y(t) be the fraction of the population that has heard the rumor at time t and assume that the rate at which the rumor spreads is proportional to the product of the fraction y of the population that has heard the rumor and the fraction 1−y that has not yet heard the rumor.

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

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

where k is the constant of proportionality, dy/dt = rate at which the rumor spreads

$\frac{dy}{dt}=ky(1-y)\\\frac{dy}{y(1-y)}=kdt\\\int\limits {\frac{dy}{y(1-y)}} \, =\int\limit {kdt}\\\int\limits {\frac{dy}{y}} +\int\limits {\frac{dy}{1-y}} =\int\limit {kdt}\\\\ln(y)-ln(1-y)=kt+c\\ln(\frac{y}{1-y}) =kt+c\\taking \ exponential \ of\ both \ sides\\\frac{y}{1-y} =e^{kt+c}\\\frac{y}{1-y} =e^{kt}e^c\\let\ A=e^c\\\frac{y}{1-y} =Ae^{kt}\\y=(1-y)Ae^{kt}\\y=\frac{Ae^{kt}}{1+Ae^{kt}} \\at \ t=0,y=10\%\\0.1=\frac{Ae^{k*0}}{1+Ae^{k*0}} \\0.1=\frac{A}{1+A} \\A=\frac{1}{9} \\$

$y=\frac{\frac{1}{9} e^{kt}}{1+\frac{1}{9} e^{kt}}\\y=\frac{1}{1+9e^{-kt}}$

At t = 2, y = 40% = 0.4

c) At y = 75% = 0.75

$y=\frac{1}{1+9e^{-0.8959t}}\\0.75=\frac{1}{1+9e^{-0.8959t}}\\t=3.68\ days$

5 0

3 years ago

To graph the equation 2x + 5y = 10, Zeplyn draws a line through the points (5, 0) and (0, What is the slope of the line represen

wariber [46]

Answer: -2/5

Step-by-step explanation:

To find the slope, we set the function use y = mx + b forms.

2x + 5y = 10

5y = -2x + 10 Minus 2x in both side

y = -2/5x + 10/5 Divide 5 from both side

y = -2/5x + 2

In the y = mx + b, the m before variable x is always the slope, so -2/5 is the slope for 2x + 5y = 10.

8 0

3 years ago

R is the midpoint of QS, if QR=2x and RS=x+3, what is RS?

lbvjy [14]

Q -------------R------------S

suppose this is your line,

R is the mid point

and it's given that

QR = 2x
and
RS = x+3

as R is the mid point of QS
so,
QR = RS
then,
2x = x + 3
2x - x =3
x = 3

as,
it's given that RS = x + 3
then,
RS = 3 + 3
= 6 units.

5 0

3 years ago

Kyle is pulled back on a swing so that the rope forms an angle of 30° with the vertical. The distance from the top of the swing

olga_2 [115]

This would be 12 - 12*cos(30) = 12 - 6 $\sqrt{3}$ = 1.608 ft off the ground.

6 0

3 years ago