\[ f=\{(-1,1),(1,-2),(3,-4)\} \] and \[ g=\{(5,0),(-3,4),(1,1),(-4,1)\} \] \[ (f-g)(1)= \]

Step 1 ：Given functions f and g as follows:

Step 2 ：\[f=\{(-1,1),(1,-2),(3,-4)\}\]

Step 3 ：\[g=\{(5,0),(-3,4),(1,1),(-4,1)\}\]

Step 4 ：The operation \((f-g)(x)\) is defined as \(f(x) - g(x)\). So, to find \((f-g)(1)\), we need to find the values of \(f(1)\) and \(g(1)\) and then subtract \(g(1)\) from \(f(1)\).

Step 5 ：From the given, \(f(1) = -2\) and \(g(1) = 1\).

Step 6 ：Subtracting \(g(1)\) from \(f(1)\), we get \(-2 - 1 = -3\).

Step 7 ：So, \((f-g)(1) = -3\).

Step 8 ：Final Answer: \(\boxed{-3}\)