Question

The sum of two numbers is -39. One number is 21 less than the other

Answer 1

x + x-21 = 39
the numbers are 9 and 30

Answer 2

a = first number

b = second number

One number is 21 less than the other means:

b = a - 21

The sum of two numbers is - 39 of course means:

a + b = - 39

Replace b with a - 21 in this equation

a + a - 21 = - 39

2 a - 21 = - 39

Add 21 to both sides

2 a = - 18

Divide both sides by 2

a = - 9


b = a - 21

b = - 9 - 21

b = - 30


- 30 is 21 less than - 9

and

- 9 + ( - 30 ) = - 9 - 30 = - 39


So the numbers are - 9 and - 30