Given the functions f(x)=3x+2-4/x and g(x)= 2-3x

a) f(a+b)

b) g(a) - g(a-b) + f(a)

For a function f(x) = \frac{x-1}{1+x}, f(a) will be f(a) = \frac{(a) - 1}{1+(a)} = \frac{a-1}{1+a}

Similarly, f(2a+b^2-c) will be f(a) = \frac{(2a+b^2-c) - 1}{1+(2a+b^2-c)} = \frac{2a+b^2-c-1}{1+2a+b^2-c}

Does that make sense?