Simplify the equation

100 points, hi, i’m not sure how to get the equation from the graph and table.

Simplify. −4x^2 (5x^4−3x^2+x−2) −20x^6−12x^4+8x^3−8x^2 −20x^6+12x^4−4x^3+8x^2 −20x^8+12x^4−4x^2+8x −20x^6+12x^4+4x^3−8x^2

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28