Answer:

or

Step-by-step explanation:
Hello!
Use the quadratic formula: 
First, let's convert our equation to standard form of a Quadratic: ax² + bx + c = 0
3x² = 80
3x² - 80 = 0
Note, thats the value of b will be 0, as there is no "bx"
Now, solve:
Plug in values
Simplify the radical (Discriminant)
Pull out perfect squares
Reduce factors
The solutions are 
Answer:
- 6
Step-by-step explanation:
The given statement implies that the slope of line formed by (5, r) is (3, -2) is -2, as they lie on the same line.
Slope(using these pts) = (y2 - y1)/(x2 - x1)
=> - 2 = (-2 - r)/(3 - 5)
=> -2 = (-2 - r)/(-2)
=> (-2)(-2) = (-2 - r)
=> 4 = -2 - r
=> r = - 2 - 4
=> r = - 6
Answer:
The probability that an elementary or secondary school teacher selected at random from this city is a female or holds a second job is 0.90.
Step-by-step explanation:
Denote the events as follows:
<em>X</em> = an elementary or secondary school teacher from a city is a female
<em>Y</em> = an elementary or secondary school teacher holds a second job
The information provided is:
P (X) = 0.66
P (Y) = 0.46
P (X ∩ Y) = 0.22
The addition rule of probability is:

Use this formula to compute the probability that an elementary or secondary school teacher selected at random from this city is a female or holds a second job as follows:

Thus, the probability that an elementary or secondary school teacher selected at random from this city is a female or holds a second job is 0.90.
To solve the problem you must know that to change from Cartesian to polar coordinates you must write:
x = rcos (θ)
Where "r" is the radius
Likewise y = rsin (θ)
Therefore, in the expression r = 3cos (θ) one can write r as:
r = x / cos (θ)
So:
x / cos (θ) = 3cos (θ)
x = 3cos ^ 2 (θ)
The same for y ...
y = rsin (θ)
y = 3cos (θ) sin (θ).
Finally the correct answer is option 2.
x = 3cos ^ 2 (θ) y = 3cos (θ) sin (θ).