Step-by-step explanation:
[tex]g(0.5) = 2 \\ \\ h(x) = g(x).f(x) \\ \therefore \: h(2) = g(2).f(2) \\ \therefore \: h(2) = 5 \times 2\\ \therefore \: h(2) = 10\\ \\ \\ j(x) = g(x) - f(x) \\ \therefore \: j(4) = g(4) - f(4) \\ \therefore \: j(4) = 9 - 8\\ \therefore \: j(4) = 1\\ \\ \\[/tex]