David L. answered 10/08/19
Ph.D. Chemist tutoring math and science
In problems of this sort, it is always best to let x = the smaller (or, in this case, the smallest) number
From the problem, the second number is x+6.
From the problem, the third number is 2x.
The sum is given as 26, so
x + (x+6) + (2x) = 26
Simplify to get
4x + 6 = 26
4x = 20
x=5
So the three numbers are 5, 11 and 10