Help Solving quadratic equations with Square Roots mastery test but It's Edmentum so I think I need the right answer from someone who has taken it.

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

When y’all answer can y’all explain too !

Abag of jelly beans contain 13 pink, green, 20 yellow, 10 black, 7 red, and 11 orange jelly beans. approximately what percent of the jelly beans are pink and yellow?