FIRST-PERSON BRAINLIEST Which algebraic expression represents “the sum of a number and 9”?

A. n-9

B. n+9

C. 9n

D. n/9

Step-by-step explanation:

The sum of a number and 9 is adding of any variable to 9.

E.g the sum of 8 and 7

8+7=15

We can also have the sum of two unknown numbers, we can let the first number be x and the second number be y, then the sum of the two unknown will be (x+y).

So, let apply this to the question

The sum of a number and 9, since we don't the number, let the number be n, then the sum of the number and 9 will be (n+9)

Then the correct option is B which is n+9

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.