When 2bx^4+x^2-b is added to 3x^3-dx^2+cx+a the result is 6x^4+bx^3-4x^2+2x-2 find a, b,c

Acable company claims that the average household pays $78 a month for a basic cable plan, but it could differ by as much as $20. write an absolute value inequality to determine the range of basic cable plan costs with this cable company. a. |x − 78| ≥ 20 b. |x − 20| ≥ 78 c. |x − 20| ≤ 78 d. |x − 78| ≤ 20