Question 54141
It appears that you are trying to simplify a composite function.  I'm not sure why your substituting -1 and 0 into the functions unless you were given some instruction that I am unaware of.
{{{f(x)=x^2+3x-1}}}
{{{g(x)=x-1}}}
fog(x)=f(g(x))=f(x-1)  Which means you substitute the g function everywhere there's an x in the f function.
{{{f(x-1)=(x-1)^2+3(x-1)-1}}}
{{{f(x-1)=(x-1)(x-1)+3x-3-1}}}
{{{f(x-1)=x^2-x-x+1+3x-4}}}
{{{f(x-1)=x^2-x-x+3x+1-4}}}
{{{highlight(fog(x)=f(x-1)=x^2+x-3)}}}
Happy Calculating!!!