The number is 84.
Assign the digits in the number the letters a and b.
GIVEN: a + b = 12
GIVEN: a = 2b
Solve for b, then solve for a.
2b + b = 12
3b = 12
b = 4
a = 2(4) = 8
9218 9425
The number is 84.
100012
There is a lot of answer for this, but I tell you one. The answer is 6541.
12
22621, 44742, 66863, 88984
804
9218 9425
22621, 44742, 66863, 88984
81
91 since the ones digit is 8 less than 9 and the two digits, 9+1 = 10, a two-digit number.
216.
2
216
The number is 84.
100012
1