function F = fun(x)x1 = x(1);
x2 = x(2);F = [2*x1+3*x2-3;3*x1+2*x2-5];>>fsolve(@fun,[0,0])如果有变系数如下：
function F = fun(x,a,b)x1 = x(1);
x2 = x(2);F = [a(1)*x1+b(1)*x2-3;a(2)*x1+b(2)*x2-5];>>fsolve(@fun,[0,0],[],a,b);%中间加一个[],后面传参数即可