The closure property states that the sum of two polynomials is a constant

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!

x = 3 ± √(5+y)

- (2, -7)

- lines r and s and lines t and u must be parallel