sarah is demonstrating the idea that polynomials are closed under addition her work and explanation are shown part a add 3x^4+6x-7 to a 2x^3-(2x)^2+4x^-1 b (2x)^2+4.4x-9 x(-8x)^-2 -(3x)^3+7 part b is in the picture

it is x equals 3   plese mark me really need it

step-by-step explanation:

a

step-by-step explanation:

given the 2 equations

- x + y = - 2 → (1)

2x - 3y = 4 → (2)

multiplying (1) by 2 and adding to (2) will eliminate the x- term

- 2x + 2y = - 4 → (3)

add (2) and (3) term by term

(2x - 2x) + (- 3y + 2y) = (4 - 4), simplifying gives

- y = 0 ⇒ y = 0

substitute y = 0 in either of the 2 equations for corresponding value of x

substituting in (2) gives

2x = 4 ( divide both sides by 2 )

x = 2

solution is (2, 0 ) → a

2b2t

explanation:

2b2t