Let the numbers be x and y
According to the data : xy=-15 and x+y=-7
xy=-15
x+y=-7
y=-7-x
x(-x-7)=-15
y=-7-x
-x^2-7x=-15
y=-7-x
x^2+7x-15=0
y=-7-x
x=(-7±sqrt(7*7+4*15))/2
y=-7-x
x=(-7±sqrt(109))/2
Goes to two systems.
1)
y=-7-x
x=(-7+sqrt(109))/2
y=-7+3.5-sqrt(109))/2
x=(-7+sqrt(109))/2
y=-3.5-sqrt(109))/2
x=(-7+sqrt(109))/2
2)
y=-7-x
x=(-7-sqrt(109))/2
y=-7+3.5+sqrt(109))/2
x=(-7-sqrt(109))/2
y=-3.5+sqrt(109))/2
x=(-7-sqrt(109))/2
