We have to calculate the difference of the given polynomials, we follows as:

After opening the brackets, the signs of all the terms changes as there is negative sign before the bracket.
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Combining all the like terms, we get as
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Option A is the correct answer.
Here you go this is all you are doing
Plug in n = 1 into the nth term formula
a(n) = 4n-1
a(1) = 4*1-1
a(1) = 3
So the first term is 3
The second term will be 7 because we add on 4 each time, as indicated by the slope of 4. This is also known as the common difference.
So the nth term is found by adding 4 to the (n-1)st term, in other words,
a(n) = a(n-1)+4
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In summary, the answer is
a1=3; an=an-1+4
which is choice B
X^2 = 81...take the square root of both sides, eliminating the ^2
x = (+-) sqrt 81
x = (+-) 9
answers are : -9 and 9