Answer:
(n + 7)(-3)
3(n - 7)
7(n - 3)
Explanation:
We are given worded expressions and are asked to match the algebraic expression that goes along with it.
Let's look at the first, "Negative three times the sum of a number and seven"
Our keywords here are negative, times, and sum.
These three indicate that there is a negative number, multiplication, and addition.
Start off with a negative three, of course, the value is -3, and it is alone.
Followed with the word times, this means that -3 is valued by itself and is not being added or subtracted by any other number.
Now the sum of a number and seven proves that these two must be grouped together, therefore our answer is (n + 7)(-3)
Now for the second, "Three times the difference of a number and 7"
Our keywords are times and difference
There is a multiplication and subtraction problem within this expression
So first, three times shows that the value 3 is alone.
Followed by the difference of a number and 7, meaning that the number (n) and 7 are in an expression as themselves and should be grouped.
Our answer is 3(n - 7)
Onto the last, "Seven times the sum of a number and negative three"
Our keywords are times, sum, and negative
Just like the first, there is an addition, multiplication, and negative number
Seven times indicates that the value 7 is alone
The sum of a number shows that this is a separate group, followed with negative three, n is being added to negative three
With the combination of another group and the addition problem, our answer is 7(n - 3)