Solve the system by substitution.
-2y = x
7x+9y = -45

Recall the definition of a polynomial expression. find two polynomial expressions whose quotient, when simplified,is. use that division problem to determine whether polynomials are closed under division. then describe how theother three operations-addition, subtraction, and multiplication-are different from division of polynomials.

12 point are triangles pqr and stu congruent? what is the congruency that proves they are congruent? what is the perimeter of triangle pqr?

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)