Someone do this and explain for brain liest :D explain how u do it and yes

To solve the system of equations below, grace isolated the variable y in the first equation and then substituted into the second equation. what was the resulting equation? 3y=12x x^2/4+y^2/9=1

Olga used 100 ounces of flour to make 225 muffins. how many ounces of flour will be used to make 300 muffins?

6x + 3y = -6 2x + y = -2 a. x = 0, y = -2 b. infinite solutions c. x = -1, y = 0 d. no solution