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Naddika [18.5K]

3 years ago

11

You are mowing a lawn. After 12 minutes, 52% of the lawn still needs mowed. How long does it take to mow the entire lawn? Write

an equation that represents the percent y of the lawn that still needs mowed after x minutes.

1 answer:

aleksley [76]3 years ago

7 0

12/x = 52/48
12 * 48 = 52x
x = 11.07 This is one way to do it.

Let the time = x
Let the part of the lawn = y

The general equation
y = k*x
52/100 = k * 12
k = 0.043333
y = 0.043333*x
y = 0.043333* 11.08
y = 0.48 which is what it should be.

Yet another way is to let y = kx
52 = k*12
k = 52/12
k = 4.33333333

y = 4.333333 * x
y = 4.333333 * 48
48 = 4.333333 * x
x = 11.07 which is just what you should expect.

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sergiy2304 [10]

D. 800(3.14) cm cubed

7 0

3 years ago

The French Club is sponsoring a bake sale. If their goal is to raise at least $140, how many pastries must they sell at $3.50 ea

Schach [20]

It will be b because you will have to time $3.50P140= 490

8 0

3 years ago

Riverside Elementary School is holding a school-wide election to choose a school color. Five-eighths of the votes were for blue,

Mnenie [13.5K]

Answer:

Step-by-step explanation:

Let the total number of votes to choose a color = x

Number of votes for blue = $\frac{5}{8}\times x$

Remaining votes = x - $\frac{5}{8}\times x$

= $\frac{8x-5x}{8}\times x$

= $\frac{3}{8}\times x$

Votes for green = $\frac{5}{9}\times (\text{Remaining votes})}$

= $\frac{5}{9}\times \frac{3x}{8}$

= $\frac{5}{24}\times x$

Finally remaining votes = $\frac{3x}{8}-\frac{5x}{24}$

= $\frac{9x-5x}{24}$

= $\frac{4x}{24}$

= $\frac{x}{6}$

Since these votes are for red therefore,

$\frac{x}{6}$ = 48

x = 48×6

= 288

a) Votes for blue are $\frac{5x}{8}$

Therefore, exact number for blue votes = $\frac{5\times 288}{8}$

= 5×36

= 180

b). Votes for green = $\frac{5x}{24}$

= $\frac{5\times 288}{24}$

= 60

c). Since 25 students were absent on that day of the vote, number of students at Riverside Elementary School = 288 + 25

= 313

d). Since seven tenths of the votes for blue were made by the girls.

Therefore, number of girls voted for blue = $\frac{7}{10}\times 180$

= 7×18

= 126

Since total votes made = 288

Therefore, half of the votes made = $\frac{288}{2}$

= 144

Now it's clear that number of votes made by girls is less than half of all the votes.

e). 126 girls voted for blue.

5 0

3 years ago

F⃗ (x,y)=−yi⃗ +xj⃗ f→(x,y)=−yi→+xj→ and cc is the line segment from point p=(5,0)p=(5,0) to q=(0,2)q=(0,2). (a) find a vector pa

DerKrebs [107]

a. Parameterize $C$ by

$\vec r(t)=(1-t)(5\,\vec\imath)+t(2\,\vec\jmath)=(5-5t)\,\vec\imath+2t\,\vec\jmath$

with $0\le t\le1$ .

b/c. The line integral of $\vec F(x,y)=-y\,\vec\imath+x\,\vec\jmath$ over $C$ is

$\displaystyle\int_C\vec F(x,y)\cdot\mathrm d\vec r=\int_0^1\vec F(x(t),y(t))\cdot\frac{\mathrm d\vec r(t)}{\mathrm dt}\,\mathrm dt$

$=\displaystyle\int_0^1(-2t\,\vec\imath+(5-5t)\,\vec\jmath)\cdot(-5\,\vec\imath+2\,\vec\jmath)\,\mathrm dt$

$=\displaystyle\int_0^1(10t+(10-10t))\,\mathrm dt$

$=\displaystyle10\int_0^1\mathrm dt=\boxed{10}$

d. Notice that we can write the line integral as

$\displaystyle\int_C\vecF\cdot\mathrm d\vec r=\int_C(-y\,\mathrm dx+x\,\mathrm dy)$

By Green's theorem, the line integral is equivalent to

$\displaystyle\iint_D\left(\frac{\partial x}{\partial x}-\frac{\partial(-y)}{\partial y}\right)\,\mathrm dx\,\mathrm dy=2\iint_D\mathrm dx\,\mathrm dy$

where $D$ is the triangle bounded by $C$ , and this integral is simply twice the area of $D$ . $D$ is a right triangle with legs 2 and 5, so its area is 5 and the integral's value is 10.

4 0

3 years ago

A population of a particular yeast cell develops with a constant relative growth rate of 0.4225 per hour. The initial population

Ksju [112]

Answer: The population after 3 hours is 13.9 mill.

Step-by-step explanation:

When we have an exponential with:

A = initial population.

r = constant relative growth rate:

t = time.

The function that models this is:

P(t) = A*e^(k*t)

In this case we know that:

A = 3.9 mill.

r = 0.4225 1.

Then the function that models the population of this yeast cell is:

P(t) = (3.9 mill)*e^(0.4225*t)

where t represents the time in hours.

Then if we want to know the population after 3 hours, we should replace t by 3.

P(3) = (3.9 mill)*e^(0.4225*3) = 13.85 mill.

And we want to round our answer to one decimal place, then we must look at the second decimal place, we can see that is a 5, so we should round up.

The population after 3 hours is 13.9 mill.

8 0

3 years ago