SOLUTION: The sum of the digits of a 2 digit number is 6. The second digit is twice the first digit. Find the 2 digit number

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Question 710037: The sum of the digits of a 2 digit number is 6. The second digit is twice the first digit. Find the 2 digit number
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
If you are in the lower grades:

The sum of the digits of a 2 digit number is 6. 

So it's either 15, 24, 33, 42, or 51.

The second digit is twice the first digit. 

So it's 24.

If you are in the upper grades,

t = the tens digit
u = the units digit

The system to solve is:

system%28t%2Bu+=+6%2C%0D%0Au+=+2t%29

Substitute 2t for u in the first equation:

t+2t = 6
  3t = 6

Divide both sides by 3

 3t%2F3 = 6%2F3

 cross%283%29t%2Fcross%283%29 = cross%286%29%5E2%2Fcross%283%29

 t = 2

u = 2t = 2(2) = 4

u = 4

The number = 24

Edwin