Question

Find two numbers, if their sum is 3 and their difference is 21.

Answer 1

Answer:

12  and -9 that my answers

Step-by-step explanation:

Answer 2

Answer:

12 & -9

Step-by-step explanation:

So you make two equations:

x+y=3  because their sum is 3

x-y=21 because their difference is 21

Now you have to solve one equation, I'll use the first one

x=3-y

Plug in this x into the other equation

x-y=21

(3-y)-y=21

3-2y=21

-2y=18

y=-9

Now solve for the other number

x-9=3

x=12

Your numbers would be 12 and -9  c: