What two number multiply to -21 and add to 20

-1 and 21

Step-by-step explanation:

Let the numbers be x and y.

x + y = 20

xy = -21

Solve the first equation for x and substitute in the second equation.

x = 20 - y

(20 - y)y = -21

20y - y^2 = -21

y^2 - 20y - 21 = 0

(y - 21)(y + 1) = 0

y - 21 = 0 or y + 1 = 0

y = 21 or y = -1

For y = 21:

x = 20 - y

x = 20 - 21

x = -1

For y = -1:

x = 20 - y

x = 20 - (-1)

x = 21

Solutions: (-1, 21) and (21, -1)

the numbers are -1 and 21

what do you need me to answer?

step-by-step explanation:

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.