Question 125690
One number (let it be {{{x}}}) is {{{12}}} more than another(let it be {{{y}}}).

assume {{{x<y}}}, then {{{y = x + 12}}}

The sum of the smaller number and twice the larger number is {{{39}}}:

{{{x + 2y = 39}}}

since {{{y =x + 12}}}, we will have;

{{{x + 2(x + 12)= 39}}}

{{{x + 2x + 24 = 39}}}

{{{ 3x  = 39 -24}}}

{{{ 3x  = 15}}}

{{{ x  = 5}}}

  the larger number will be:

{{{y =x + 12}}}

{{{y = 5 + 12}}} 

{{{y =  17}}} 

check:

{{{x + 2y = 39}}}...plug in {{{x}}} and {{{y}}}

{{{5 + 2(17)= 39}}}

{{{5 + 34 = 39}}}

{{{39 = 39}}}