The general equation for computing the circumference of a circle is

, where C is the circumference, and d is the diameter. (You might also see the equation as

where r is the radius, because

)
Computing the circumferences of the two circles, we get:


.
To calculate the ratio of two numbers, we can divide one by the other. You can look at this as "How many times does the denominator fit in the numerator?"

So the circumference of the complex impact crater is 2 times greater than the circumference of the simple impact crater.
You could complete the square to state the vertex.
You could use the quadratic equation to find the roots (which are complex).
Try an example that will require both.
y = x^2 + 2x + 5
Step One
Get the graph. That's included below.
Step Two
Provide the steps for completing the square.
Note: we should get (-1,4)
y= (x^2 +2x ) + 5
y = (x^2 +2x + 1) + 5 - 1
y = (x +1)^2 + 4
The vertex is at (-1,4)
Step Three
Find the roots. Use the quadratic equation. Note that the graph shows us that the equation never crosses or touches the x axis. The roots are complex.

a = 1
b = 2
c = 5




x = -1 +/- 2i
x1 = -1 + 2i
x2 = -1 - 2i And we are done.
To find what profit they made, subtract what they earned from what they spent money on. 275-55=220. They made a total of $220 after paying for supplies. I hope this helps! :)
The general equation for any circle with its center at point (a, b) is
(x - a)² + (y - b)² = (radius)²
So the circle in the question is centered at (-3, -4), and its radius is 3 .