1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Serggg [28]
2 years ago
13

Three-fourths of the 8th graders at Kingston

Mathematics
1 answer:
Ganezh [65]2 years ago
6 0

sAnswer:189 students

Step-by-step explanation:

You might be interested in
Find the average of the following salaries:<br> $38,750.00, $42,500.00, $44,500.00
sertanlavr [38]
To find the average you add all three numbers together and then divide by three since you added three.
$38,750.00 + $42,500.00 + $42,500.00 = $123,750.00
$123,750.00 ÷ 3 = $41,250
So your answer is $41,250

4 0
3 years ago
A circle has the order pairs (-1, 2) (0, 1) (-2, -1) what is the equation . Show your work.
olga55 [171]
We know that:

(x-a)^2+(y-b)^2=r^2

is an equation of a circle.

When we substitute x and y (from the pairs we have), we'll get a system of equations:

\begin{cases}(-1-a)^2+(2-b)^2=r^2\\(0-a)^2+(1-b)^2=r^2\\(-2-a)^2+(-1-b)^2=r^2\end{cases}

and all we have to do is solve it for a, b and r.

There will be:

\begin{cases}(-1-a)^2+(2-b)^2=r^2\\(0-a)^2+(1-b)^2=r^2\\(-2-a)^2+(-1-b)^2=r^2\end{cases}\\\\\\&#10;\begin{cases}1+2a+a^2+4-4b+b^2=r^2\\a^2+1-2b+b^2=r^2\\4+4a+a^2+1+2b+b^2=r^2\end{cases}\\\\\\&#10;\begin{cases}a^2+b^2+2a-4b+5=r^2\\a^2+b^2-2b+1=r^2\\a^2+b^2+4a+2b+5=r^2\end{cases}\\\\\\&#10;

From equations (II) and (III) we have:

\begin{cases}a^2+b^2-2b+1=r^2\\a^2+b^2+4a+2b+5=r^2\end{cases}\\--------------(-)\\\\a^2+b^2-2b+1-a^2-b^2-4a-2b-5=r^2-r^2\\\\-4a-4b-4=0\qquad|:(-4)\\\\\boxed{-a-b-1=0}

and from (I) and (II):

\begin{cases}a^2+b^2+2a-4b+5=r^2\\a^2+b^2-2b+1=r^2\end{cases}\\--------------(-)\\\\a^2+b^2+2a-4b+5-a^2-b^2+2b-1=r^2-r^2\\\\2a-2b+4=0\qquad|:2\\\\\boxed{a-b+2=0}

Now we can easly calculate a and b:

\begin{cases}-a-b-1=0\\a-b+2=0\end{cases}\\--------(+)\\\\-a-b-1+a-b+2=0+0\\\\-2b+1=0\\\\-2b=-1\qquad|:(-2)\\\\\boxed{b=\frac{1}{2}}\\\\\\\\a-b+2=0\\\\\\a-\dfrac{1}{2}+2=0\\\\\\a+\dfrac{3}{2}=0\\\\\\\boxed{a=-\frac{3}{2}}

Finally we calculate r^2:

a^2+b^2-2b+1=r^2\\\\\\\left(-\dfrac{3}{2}\right)^2+\left(\dfrac{1}{2}\right)^2-2\cdot\dfrac{1}{2}+1=r^2\\\\\\\dfrac{9}{4}+\dfrac{1}{4}-1+1=r^2\\\\\\\dfrac{10}{4}=r^2\\\\\\\boxed{r^2=\frac{5}{2}}

And the equation of the circle is:

(x-a)^2+(y-b)^2=r^2\\\\\\\left(x-\left(-\dfrac{3}{2}\right)\right)^2+\left(y-\dfrac{1}{2}\right)^2=\dfrac{5}{2}\\\\\\\boxed{\left(x+\dfrac{3}{2}\right)^2+\left(y-\dfrac{1}{2}\right)^2=\dfrac{5}{2}}
7 0
3 years ago
Solve the system by the elimination method.<br><br> 2a + 3b = 6<br> 5a + 2b - 4 = 0
mariarad [96]
2a + 3b = 6 --> Equation 1
5a + 2b = 4 --> Equation 2
Equation 1 * 5 --> 10a + 15b = 30
Equation 2 * 2 --> 10a + 4b = 8
Equation 1 - Equation 2 --> 11b = 22 --> b = 2
Sub b=2 in Equation 1 (or 2, either works):
2a + 3b = 6
2a + 3(2) = 6
2a + 6 = 6
2a = 0
a = 0

b = 2, a = 0

5 0
3 years ago
Read 2 more answers
If 9x83=747 then 747+9+83=?
strojnjashka [21]

Answer:

747+9+83=839

Step-by-step explanation:

We can use 9x83=747 as a extra help to get the answer. Say you need the answer above (which I gave you) so you get 9x83 as an example to help figure out 749+9+83=839.

4 0
3 years ago
Solve the following systems of 3-variable linear equations.​
Dima020 [189]

Answer:

.

Step-by-step explanation:

3 0
3 years ago
Other questions:
  • Given ƒ(x) = 2x2 − 3x + 7, find ƒ(2.5)
    8·2 answers
  • Which number produces a rational number when multiplied by 1/5 ?
    5·2 answers
  • What is the volume of the prism​
    8·2 answers
  • Find the total profit or loss for each color of T-shirt.
    5·1 answer
  • Two of the angles in a triangle measure 35 and 8. What is the measure of the third angle?
    14·1 answer
  • According to a certain country’s department of education, 40.0% of 3-year-olds are enrolled in day care.
    11·1 answer
  • If you have two nickels and two dimes and nine pennies how much will that be
    13·1 answer
  • Find the slope of the altitude on each side of triangle ABC (a) A(1,0), B(-3, 4),C(-1,-3)<br>​
    12·1 answer
  • I am learning to make meme what u think?
    8·2 answers
  • Please help and thank you
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!