Find two pairs of consecutive odd integers whose product is 63.

Question

Can you tell me how to do this please.

Answer 1

I can answer this based on knowledge of composite numbers: 7 times 9 = 63.

 

The only other pair of numbers satisfying this is -7 and -9.

Answer 2

If you need to see a systematic solution, let the 2 numbers be n and n + 2.

 

n(n + 2) = 63

 

n² + 2n - 63 = 0

 

(n - 7)(n + 9) = 0

 

n = 7 or -9

 

If n = 7, then n + 2 = 9

If n = -9, then n + 2 = -7

 

There are your two pairs, {7,9} and {-7,-9}, the same as in Kenneth's answer.