Round to the nearest hundredth 7.381

To solve the system of equations below, pedro isolated the variable y in the first equation and then substituted it into the second equation. what was the resulting equation? { 5y=10x {x^2+y^2=36

I’m stuck on this equation, anyone got the answer?

Rewrite the following quadratic functions in intercept or factored form. show your work. y = 5x^2 + 10x