What is an algebraic expression for 18 more than a number n

Which expression is equivalent to 2x^2+2x-4/2x^2-4x+2

Pick the expression that matches this description: a polynomial of the 5th degree with a leading coefficient of 7 and a constant term of 6 (choice a) 7x^5+2x^2+6 (choice b) 7x^6−6x^4+5 (choice c) 6x^7−x^5+5 (choice d) 6x^5+x^4+7

Which value is not a solution of 8x^3 – 1 = 0