Solve the simultaneous equation
x+y=1
x squared + y squared=25
Use the substitution method for solving systems of equations.
1. Solve the first equation for x (or y). You won't get a numerical value.
2. Then, plug in what you got in step 1 into the second equation to solve for y (or x, depending on which you solved for).
3. Then, plug y (the numerical value) into the first equation to solve for x.