what two number you multiply to get 1800 and also subtract to get answer -50

$$\\xy=1800 \;\;(1a)
\\x-y=-50\;\; (2a)\\
x=-50+y\;\; (2b)\\
sub\; 2b\; into\; 1a\\
(-50+y)y=1800\\
y(y-50)=1800\\
y^2-50y-1800=0\\\\
y=\frac{50\pm\sqrt{2500+7200}}{2}\\\\
y=\frac{50\pm\sqrt{9700}}{2}\\\\
y=\frac{50\pm10\sqrt{97}}{2}\\\\
y=25\pm5\sqrt{97}\\\\$$

x=-50+y

$$\\If\;\; y=25+5\sqrt{97}\;\;\;x=-25+5\sqrt{97}\\\\
If\;\; y=25-5\sqrt{97}\;\;\;x=-25-5\sqrt{97}\\\\$$

you should check these answers by checking xy=1800

I checked on of them it was fine.