Problema Solution
The product of two consecutive positive odd integers is 143. Find the integers.
Answer provided by our tutors
Every odd number can be written in a 2k+1 form where k is integer.
Thus for the two consecutive positive odd integers we can write: 2k+1 and 2k+3
the product of this two numbers is 143 that is
(2k + 1)(2k + 3) = 143
4k^2 + 5k - 140 = 0
by solving this quadratic equation we find
k1 = 5
k2 = -7 it is not a solution since we need k >0.
For k = 5 the consecutive positive odd integers are:
2*5 + 1 = 11
2*5 + 3 = 13
and indeed 11*13 = 143
The numbers that we are looking for are 11 and 13.