Help?? Or not but help? No links ;-;

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

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)

Damon makes 20 cups of lemonade by mixing lemon juice and water. the ratio of lemon juice to water is shown in the tape diagram. lemon juice\text{lemon juice} lemon juice water\text{water} water how much lemon juice did damon use in the lemonade? cups