If you live long enough (and well enough!),
then eventually you are going to have to solve for x. It's unavoidable.
Get used to it. Below are a variety of examples involving both
symbolic and numerical solutions of equations and systems of equations.
Enjoy!
Here are the functions and expressions.
> restart;
> y1:=2*x+5;
> y2:=-x+10;
> y3:=x^3-x^2+x-2;
> f:=x->x^2-x-1;
> g:=x^2+y^2;
Here are the solutions.
> solve(y1=0, x);
> solve({y=y1,y=y2},{x,y});
> p:=solve(y3=0, x);
> p[1];
> evalf(p[1]);
> solve(f(x)=0, x);
> solve(g=1, y);
And now, here are the floating point solutions (more or less).
> fsolve(y1=0, x);
> fsolve({y=y1,y=y2},{x,y});
> fsolve(y3=0, x);
> fsolve(y3=0, x, complex);
> fsolve(y3=0, x, 0..2);
> fsolve(f(x)=0, x);
>