I don't understand how to get the answer because the equation is funky?

What are the x-coordinates of the solutions to this system of equations?

x^2 + y^2 = 25
y = 2x - 5

Question

I don't understand how to get the answer because the equation is funky?

What are the x-coordinates of the solutions to this system of equations?

x^2 + y^2 = 25
y = 2x - 5

kaylaprincess · Answer

I know to plug in y into x^2 + y^2 = 25, im just confused because the square i think?

phi · Answer

the first equation is a circle
the second is a line
they are asking where the line crosses the circle.

kaylaprincess · Answer

so all i needed to do was graph it lol

phi · Answer

yes, it is a bit ugly

but y= 2x-5
so you can replace y in the first equation
$$ x^2 + (2x-5)^2 = 25$$

kaylaprincess · Answer

this is a bit further question, but could i  just square root the equation and get rid of the squares?

phi · Answer

no, the square root of a sum is ugly

you have to expand (2x-5)(2x-5)
as the first step

kaylaprincess · Answer

then plug in y?

kaylaprincess · Answer

ohh. okay. well thank you as always.

phi · Answer

you should get
(2x-5)(2x-5)=  4x^2 -20x + 25
so the equation is now
$$ x^2 + 4x^2 -20x + 25 = 25$$

phi · Answer

and here is what the problem looks like when graphed