Question

Can someone please help me figure this question out? I'm a bit confused.
Using the following equation, find the center and radius of the circle. You must show all work and calculations to receive credit.

x2 + 2x + y2 + 4y = 20

Answer 1

May I help?

Answer 2

@3mar thanks very much

Answer 3

Not at all!
You are welcome!
That is with my pleasure!

How can you start in your opinion?

Answer 4

I was using this to guide me but the third step is confusing me with this particular equation. lol

Answer 5

Yes, this is what I was going to start to do with you: Completing the squares/quadratics!

Answer 6

@3mar great, at least i have the correct start lol! x2 + 2x + y2 + 4y = 20 is the given equation so I need to make that standard form to figure out the center and radius. So I made this into (x2 + 2x) + (y2 +4y) = 20

Answer 7

but then that picture i sent above confuses me since the third step doesn't make sense to me

Answer 8

"So I made this into (x2 + 2x) + (y2 +4y) = 20"
That is awesome!

let me simplify the nest step, ok?

Answer 9

@3mar thank you, i do need some clarification of it!

Answer 10

Pleasure is mine!
I will do my best!

Let's have an example!

what we can put in the empty rectangles (add it and subtract it without changing anything in the expression) to have a complete square like that \((x+....)^2\)??