Answer:
3x + 2x - x = 4x
3(x+3) = 3x + 9
6x - 3 + 2(x-9) = 8x - 21
Step-by-step explanation:
For the first question, we add 3x and 2x, getting 5x, then subtract x, getting 4x.
For the second question, we distribute 3 to the part in parentheses, getting us the new expression, 3x+9.
For the last question, first we need to distribute 2. We then get 6x - 3 + 2x - 18. We can then combine like terms, and we get 8x - 21.
