The explicit formula of an arithmetic sequence:

We have:

Substitute:

Answer: an = 30n - 130
For number one I would recommend using an app called math papa it works really well with algebra and etc
Answer:
3 x -3y = -9y
3 x -1 = -3
The factored expression is 3(-3y - 1)
Step-by-step explanation:
All you have to do is -9y / 3 = -3y and -3 / 3 = -1, then put those numbers in parentheses. All of that is multiplied by 3.
The reason is because if you distributed the 3 it would become:
3 * -3y + 3 * -1 = -9y - 3
About 10 to 12 students did not finish