Answer:
n=21
Step-by-step explanation:
We must find n.
Remember PEMDAS. First we must do the Parentheses. Lets do distributive property by multiplying a number that is immediately outside the parentheses with each number inside the parentheses. Lets do this one side at a time.
First lets do 5(n - 7). We get 5n - 35
Now 2(n + 14) is 2n + 28
Okay...... now we have 
Now lets do OPPOSITES!!!! We must do the opposite of each thing to both sides.
The opposite of -35 is positive 35. Lets add 35 to both sides. We get:

Now lets do the opposite of 2n which is -2n

this is looking quite nice isnt it..........
The opposite of 3 times n is 3 DIVIDED BY n. So lets divide both sides by 3

amazing.......
That means:
1) you cannot factorize it, or
2) the binomial is not the right one to be the quotient or
3) the roots of the binomial are not the roots of the polynomial
The answer is D. a1=2 an=an-1+3
To use division to find the decimal equivalent of a rational number, divide the top number by the bottom number. You will get a decimal number.