from second equation y = 18-x so:-
x(18 - x) = 30
x^2 - 18x + 30 = 0
x = 16.14, 1.86
when x = 16.14 y = 18-16.14 = 1.86
when x = 1.86, y = 16.14
so one variable = 16.14 and the other = 1.86 Answer
