The sum of two numbers is thirty-four. Using x to represent the larger of the two numbers, translate "the difference between seven more than twice the larger number and the sum of the smaller number and three" into a variable expression. Then simplify. 
With x being the larger number, the smaller number is: 34 - x
"seven more than twice the larger number" translates to: 2x + 7
"the sum of the smaller number and three" translates to: 34 - x + 3, or 37 - x
"the difference between seven more than twice the larger number and the sum of the smaller number and three" translates to:
2x + 7 - (37 - x)
2x + 7 - 37 + x
Simplified form: