a+b=-7
ab=-15
a=-7-b
b(-7-b)=-15
a=-7-b
-b^2-7b+15=0
a=-7-b
b^2+7b-15=0
a=-7-b
b=(-7±sqrt(109))/2
1)
a=-7-b
b=(-7+sqrt(109))/2
b=(-7+sqrt(109))/2
a=-7+3.5-sqrt(109)/2
b=(-7+sqrt(109))/2
a=-3.5-sqrt(109)/2
2)
a=-7-b
b=(-7-sqrt(109))/2
b=(-7-sqrt(109))/2
a=-7+3.5+sqrt(109)/2
b=(-7-sqrt(109))/2
a=-3.5+sqrt(109)/2
