Question 53271
One number is 12 more than another. The sum of the smaller number and twice the larger is 39. Find the larger number.
:
Let x = "one number the (larger)"; let y = "another" number
:
Write a simple expression for each sentence:
:
"One number is 12 more than another"
   x = 12 + y
:
"sum of the smaller number and twice the larger is 39" 
   y + 2x = 39
:
1st equation states that x = (12 + y), so substitute [y+12] for x in the 2nd eq
   y + 2(y+12) = 39
   y + 2y + 24 = 39
            3y = 39 - 24
             y = 15/3
             y = 5
:
x = 12 + 5
x = 17
:
Check: 
"sum of the smaller number and twice the larger is 39."
    5 + 2(17) = 39