How to solve the system of equations x^2+(y-7)=4

Ewa:  This is not a system of equations; it's just ONE equation.  You can't 
"solve" it.  However, you could make a table of x and y values that would enable you to graph this relationship.  Example:  If x=0, y-7=4, or y=11.
Thus, (0, 11) is a point on the graph of this relationship.

Are you sure there wasn't a second equation?  If you have a second equation, then the chances are you could solve the system of equations.