3x
3 + x
x3
x + 3 + x
Answer:
x + 3 + x
Step-by-step explanation:
The sum of three terms means that three terms have been added.
3x is the answer; it does not show the terms being added.
3+x is the sum of two terms.
x³ is a product.
x+3+x shows 3 things being added, so it is the correct answer.
Answer:
x+3+x
Step-by-step explanation:
Answer:
51
Step-by-step explanation:
30 - (-21)
30 + 21
51