product of integers

Question

The sum of two consecutive integers is -15. What is the product of the two integers?

Answer 1

n+n+1=-15

2n+1=-15

2n=-15-1

2n=-16

n=-8

n+1=-7

-8*(-7)=56

 

Answer 2

Let the two consecutive integers be n and n + 1.

 

Given:

 

n + (n + 1) = -15

 

Solve for n and get 

 

2n + 1 = -15 ⇒ n = -8

 

Then the product of the two numbers is

 

n(n + 1) = -8(-8 + 1) = -8(-7) = 56