If the function f (x) has f (x) + 2F (- 1 / x) = - 3x for all real numbers with X ≠ 0, find the analytic expression of F (x)

If the function f (x) has f (x) + 2F (- 1 / x) = - 3x for all real numbers with X ≠ 0, find the analytic expression of F (x)

f(x)+2f(-1/x)=-3x (1)
x=-1/x
f(-1/x)+2f(x)=-3*(-1/x) (2)
2 * (2) - (1) get
3f(x)=-6*(-1/x) +3x
f(x)= x+2/x