I’ll explain part A and you can apply it to the other parts. The functions f(x), g(x), and m(x) are all equivalent to the given polynomials. So when it asks for f(x) + [g(x) - m(x)] you plug them in. The answer to Part A is 3x^2 +5x - z + [5x^2-3x+z - 2x^2 - 2x]. Combine the like terms (3x^2+5x^2-2x^2 = 6x^2 (because 3+5-2=6)) and so on until you’ve simplified it as much as possible!
