Final answer:
The algebraic equation formed from the problem statement is -4 + x = 81. Solving for 'x' gives us x = 85.
Step-by-step explanation:
The student's question involves creating an algebraic equation from a given word problem. The word problem states "The sum of negative four and a number is eighty-one." This translates to the algebraic equation -4 + x = 81, where 'x' represents the unknown number we are trying to find. To solve for 'x', we would add 4 to both sides of the equation, resulting in x = 85.