Find the numbers

Question

The product of two consecutive odd integers is 399. Find the integers.

Answer 1

x and x+2 are the integers

x*(x+2)=399

x²+2x=399

x²+2x-399=0

399=3*133=3*7*19=(3*7)*(19)=21*19 and 21-19=2 (you basically have the answer right here !!!)

factor

(x+21)(x-19)=0

x-19=0

x=19

x+2=21

x+21=0

x=-21

x+2=-19

there are 2 solutions, 19 and 21, and -19 and -21

using simple arithmetic...

√399=19.97..., so the integers are 19 and 21 again (and -19, -21)