Answer: Common Difference = -4 Step-by-step explanation: Formula of a term in an AP is nTh term = a + (n-1) d where a is the first term of that AP and d is the common difference of the AP. Therefore, a20 = a + 19d and a12 = a +11d therefore a + 19d – a – 11d = -32 8d = -32 d = -4 Reply
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Answer:
Common Difference = -4
Step-by-step explanation:
Formula of a term in an AP is
nTh term = a + (n-1) d
where a is the first term of that AP and d is the common difference of the AP.
Therefore,
a20 = a + 19d
and
a12 = a +11d
therefore
a + 19d – a – 11d = -32
8d = -32
d = -4