math
posted by becky on .
My thousands digit is twice my hundreds digit. The sum of my tens and ones digit is my thousands digit. My hundreds digit is 2 more than my tens digit. My tens digit is greater than 1 and less than 3. What 4 digit number am I?

8,426.
Let x represent the hundreds digit.
My thousands digit is twice my hundreds digit > Thousands= 2X
Hundreds= X
My hundreds digit is 2 more than my tens digit. > Tens= X2
Ones= Y
The sum of my tens and ones digit is my thousands digit. > 2X=(X2)+Y
My tens digit is greater than 1 and less than 3> Since it must be a whole number. 1<x<3, then x2=2 so x=4
Plug in 4 for x to get the thousands, and tens. Then solve 2X=x2+y to get the ones.
Answer is 8,426. 
I am a 3 digit number greater than 500 my tens digit is double my ones digit and half my hundreds digit what number am i