It looks like you've uploaded an image of handwritten equations. Let me extract and interpret the mathematical content.

The image contains the following system of equations:

1. $3x_1 + 4x_2 + 3x_3 - 4x_4 = 12$
2. $2x_1 + 5x_2 - 3x_3 + x_4 = 2$
3. $-3x_1 + 4x_2 - 3x_3 + x_4^2 = 2$
4. $x_1^2 + 3x_2 + x_3 - x_4 = 4$

These seem to be a system of linear and nonlinear equations. Would you like help solving them or analyzing them further?

If you'd like further details, let me know! Would you like me to explain any specific part of the system or proceed with solving the equations?

Related Questions:

1. How can I solve a system of linear and nonlinear equations?
2. What methods are best for solving systems of nonlinear equations?
3. How do I analyze the structure of a nonlinear system of equations?
4. What is the role of square terms in a system of equations?
5. Can I solve this system using matrix methods?

Tip: When solving nonlinear equations, sometimes substituting or graphing can give an insight into possible solutions before starting formal algebraic methods.