Solve this system of equations algebraically:
y + x = 19 – x2
x + y = 80
1. isolate one variable in the system of equations. y = –x2 – x + 19
y = –x + 80
2. use substitution to create a one-variable equation. –x + 80 = –x2 – x + 19
3. solve to determine the unknown variable in the equation.

the system has
real number solution(s).