Question

Translate the following verbal expression into an algebraic expression.

“Three times the sum of a number and seven”

Answer 1

3 * (x + 7)

Explanation:

Mark number as x

Then the sum of a number and seven is x + 7

Three times x + 7 can be written as

3 * (x + 7)

Parentheses mean that we first add x and 7 and then multiply their sum by 3

Alternatively you can write it as 3x + 21, since

3 * (x + 7) = 3 * x + 3 * 7 = 3x + 21