What is the 23rd term of the arithmetic sequence where a1 = 9 and a5 = 23?
23rd term = a + 22d where a = first term and d = common difference common difference = (23-9) / 4 = 3.5 23rd term = 9 + 22* 3.5 = 9 + 77 = 86
follow that ok yasmeen?
do you see how I calculated the common difference d?
i think common difference is 7/2. this is becuz, 23=9+d(5-1), 23=9+5d-d, 14=4d, d=7/2. from there, plug it in. so an=9+7/2(23-1), distribute. u get ans=86
formula for arithmetic explicit is a of n=1st term+common diff(nth term-1)
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