It may be easier to start from
.. a(x +3)(x -1) = 0
.. a(x^2 +2x -3) = 0
The quadratic
.. ax^2 +bx +c = 0 will have solutions -3 and 1 for ...
.. a ≠ 0
.. b = 2a
.. c = -3a
Answer:

Step-by-step explanation:
We have the recursive formula of a sequence:

Answer:
the error is 7-6.33=0.67
the percentage of error is (0.67/7)×100≈9.5%
Do you mean as a fraction?