Question

Write an algebraic expression to represent the following phrase:
the sum of a number and 0.5

Answer 1

Let the unknown number be x.

Sum means addition, so sum of an unknown number and 0.5 = x + 0.5.

Hence, the algebraic expression is x + 0.5

Answer 2

The word "sum" implies that this equation involves the addition of two or more numbers. Using 'x' in place of "a number" and 'y' as "the sum" we get this:

y=x+.5