What can you multiply by to get 90 and add to get - 27

Let the numbers be x and y

So, xy = 90

x+y = - 27

2xy = 180

-2xy = - 180

(x+y) ² = x²+y²+2xy

(-27) ² = x² + y² + 180

729 - 180 = x² + y²

x² + y² = 549

(x-y) ² = x² + y² - 2xy

= x²+y² - 180

= 549 - 180

= 369

x - y = √369 = 19.21

x + y = - 27

2x = - 7.79 ≈ - 7.8

x = - 7.8/2 = - 3.9