how to use "fmincon" to solve huge system of equations?

Hello guys,

I want to solve system of bilinear equations in Matlab. I tried "fmincon" and it works for small examples. i have attached an example where there are 12 equations and 7 variables and as i said it works.

But I also want to solve bigger systems, like 1000 equations. Of course it does not make sense to write all 1000 equations likewise my attached example.

So I am wondering if it is possible to solve big systems with fmincon?

Or any other function?

thank you ,

Amin