Answer: The third term is -14
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Step-by-step explanation:
First term = A(1) = 20, which is given
Second term
A(n) = A(n-1) - 17
A(2) = A(2-1) - 17
A(2) = A(1) - 17 .... note: second term = (first term) - 17
A(2) = 20 - 17
A(2) = 3
Third term
A(n) = A(n-1) - 17
A(3) = A(3-1) - 17
A(3) = A(2) - 17 ... note: third term = (second term) - 17
A(3) = 3 - 17
A(3) = -14