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).