I'm not sure what your question means, but here is my interpretation of it.
x1 = [ a b c d ] where a=xa*0.003, b=log(xv)*0.3, c=log(xh)*0.3, d=log(xd)*0.3, and these are base 10 logs. I assume xa, xv, xh, xd are variables, not the product of two variables: x and one of a, v, h, d. Also, x1 is assumed to be a separate variable.
Inverted we have xa=x1/0.0003=(10000x1)/3;
xv^0.3=10^x1, so xv=xh=xd=10^(x1/0.3);
If this is not the right answer, perhaps you could clarify your question.