What two numbers multiplied together equal -420, but added together equal 1

 x * y = -420
x + y = 1x = 1 - y

y(1 - y) = -420
-y^2 + y = -420
y^2 - y - 420 = 0
(y + 20)(y - 21) = 0

y + 20 = 0       x + y = 1
y = -20            x - 20 = 1
                       x = 21

y - 21 = 0      x + y = 1
y = 21           x + 21 = 1
                     x = -20

ur 2 numbers are 21 and -20