PLZZ HELP! Will MARK BRAINLIEST IF RIGHT

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

Rewrite the following quadratic functions in intercept or factored form. show your work. f(t) = 20t^2 + 14t - 12

Im so bad at fractions they are not my best math thing to work on