Answer:
2(n +7)
Explanation:
Each part of the English description can be written using math symbols.
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sum
A sum is formed when two or more terms are added together. Here, we are told the sum is the result of adding "a number" and 7. The number can be represented by "n", and the addition is represented by a plus sign (+). The corresponding math expression is ...
n + 7 . . . . . . "the sum of a number and 7"
product
The English description tells us this sum is multiplied by two. (That is the meaning of "two times".) In algebra, we can use several different symbols to represent "times", including a centered dot (·), a centered x (×), or no symbol at all. In this last case, the factors of the product are simply written next to each other.
We want to treat the sum as a unit, so for that purpose, we wrap it in parentheses.
2×(n +7) . . . . . . . two times the sum of a number and 7
More compactly, ...
2(n +7) . . . . . . . two times the sum of a number and 7