SOLUTION: Can you please help me solve this question? My working out? It believe it has to be 2 digit two digit number in which you have to add. My Question, Two-digit numbers N su

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: Can you please help me solve this question? My working out? It believe it has to be 2 digit two digit number in which you have to add. My Question, Two-digit numbers N su      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 756857: Can you please help me solve this question?
My working out?
It believe it has to be 2 digit two digit number in which you have to add.
My Question,
Two-digit numbers N such that N+2 is also a two-digit number, the digit sum of N+2 is less the digit sum of N?
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
N=10t%2Bu
t = tens digit of N
u = units digit of N
T%2Bu = sum of digits of N

N%2B2=10t%2Bu%2B2

If u%2B2%3C10, then
u%2B2 is the units digit of N%2B2=10t%2Bu%2B2,
t is the tens digit of N%2B2,
t%2Bu%2B2%3Et%2Bu is the sum of digits of N%2B2,
and N is not a solution.

If u%2B2%3E=10 <--> highlight%28u%3E=8%29, then
the units digit of N%2B2=10t%2Bu%2B2=10%28t%2B1%29%2Bu%2B2-10 is
u%2B2-10=u-8, and
t%2B1 is the tens digit of N%2B2.
Then, the sum of digits of N%2B2 is
and N is a solution.
All numbers ending in 8 or 9 are solutions.

Examples of solutions for N: 18, 19, 28, 29, 38, 39, ...
N=18, sum of digits of 18=9, N+2=20, sum of digits of N+2 = 2
N=19, sum of digits of 19=10, N+2=21, sum of digits of N+2 = 3
N=28, sum of digits of 28=10, N+2=30, sum of digits of N+2 = 3
N=29, sum of digits of 29=11, N+2=31, sum of digits of N+2 = 4