Question 289123
The sum of three numbers is 18. 
x + y + z = 18
:
If the largest number is twice the number of the smallest +1,
z = 2x + 1
: 
and the other numbers is 3 times the largest
y = 3z
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Replace z with (2x+1)
y = 3(2x+1)
y = 6x + 3
:
In the sum equation, replace y and z
x + (6x+3) + (2x+1) = 18
9x + 4 = 18
9x = 18 - 4
9x = 14
x = {{{14/9}}}
x = 1{{{5/9}}}
:
y = 6x + 3
y = 6*{{{14/9}}} + 3
y = {{{84/9}}} + 3
y = 9{{{3/9}}} + 3
y = 12{{{3/9}}}
:
z = 2x + 1 
z = 2*{{{14/9}}} + 1
z = {{{28/9}}} + 1
z = 3{{{1/9}}} + 1
z = 4{{{1/9}}}
:
:
Check solution in the sum equation
1{{{5/9}}} + 12{{{3/9}}} + 4{{{1/9}}} = 18