Write the equation in standard form. Identity the center and radius.
x² + y2 + 8x-4y-7=0

equation;

Center (-4,2)

Radius is

Step-by-step explanation:

Since the x^2 and y^2 have the same coeffiecent this will be a circle in a form of

Where (h,k) is center

r is the radius

So first we group like Terms together

Add 7 to both sides

Since the orginal form of the equation of the circle has a perfect square we need to complete the square for each problem

and

so we have

To find our center, h is -4 and k is 2

so the center is (-4,2)

The radius is

So the radius is 3 times sqr root of 3.

it costs $20 to interview each person for a survey. find the cost to obtain a +- 3% margin of error.

step-by-step explanation:

copy and paste, put it in google

their is no graph showing

step-by-step explanation: