Answer:
r = 
Step-by-step explanation:
So we need to complete the square for both parts of the equation
First though we can add the 6 to the other side so we have x² + 2x + y² + 4y = 6
So first we can complete the square for x² + 2x
To do so we need to use
to figure out the number we need to add to both sides
In this case our b is 2, so substituting this in we get 
Here we add 1 to both sides and now we have x² + 2x + 1 + y² + 4y = 6 + 1
Now we can follow the same steps to complete the square for y² + 4y
Here our b is 4, so substituting this in we get 
Now we add 4 to both sides and now we have x² + 2x + 1 + y² + 4y + 4 = 6 + 1 + 4
Now condensing everything we have (x + 1)² + (y + 2)² = 11
The formula for a circle is (x - h)² + (y - k)² = r²
In our equation we have r² = 11
To find the radius we need to take the square root of both sides
to get r = 
Answer:
A, B, C, D
Step-by-step explanation:
A is equal to 54, B is equal to 23, C is equal to 72, and D is equal to 84.
Answer:
The other angle is 190-7x.
Step-by-step explanation:
Angles in a triangle add up to 180 degrees.
Let A be the third angle.
A + (3x-20) + (4x+10) = 180
A = 180 - (3x - 20) - (4x + 10) = 190 - 7x
Answer:
The estimate is 
Step-by-step explanation:
From the question we are told that
The sample size is n = 522
The sample proportion of students would like to talk about school is 
Given that the confidence level is 90 % then the level of significance can be mathematically evaluated as



Next we obtain the critical value of
from the normal distribution table, the value is

Generally the margin of error can be mathematically represented as

=> 
=> 
Generally the estimate the proportion of all teenagers who want more family discussions about school at 90% confidence level is

substituting values
