Answer
a) $4x+2$
b) $-2x+4$
c) $3x^2+8x-3$
d) $(x+3)/(3x-1)$
Work Step by Step
a) $(f+g)(x) = f(x)+g(x) = x+3+3x-1=4x-2$
b) $(f-g)(x) = f(x)-g(x) = (x+3)-(3x-1) = -2x+4$
c) $(f*g)(x) = f(x)g(x) = (x+3)(3x-1) = 3x^2+8x-3$
d) $(f/g)(x) = f(x)/g(x) = (x+3)/(3x-1)$