Factorise this expression as fully as possible 12x - 9x?

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

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

Angles r and s are complementary. the measure of angle r is 31 degrees. which equation can be used to find angle s?