Plz help i dont understand this at all

Evaluate the expression for the given value of the variable 7a - 4a for a =8

Find the solution set of this inequality. enter your answer in interval notation using grouping symbols. |8x-4| ≤ 12

Select the correct answer from each drop-down menu. consider the following polynomials equations. 3x^2(x-1) and -3x^3+ 4x^2-2x+1 perform each operation and determine if the result is a polynomial. is the result of a + b a polynomial? yes or no is the result of a - b a polynomial? yes or no is the result of a · b a polynomial? yes or no