Question

If an ap if common difference -4and the 7 term is 4 than find the first term

Answer 1

Given,
$\bf \: d = - 4 \\ \bf \: a_{7} = 4$

Now,

$a_{7} = 4 \\ \\ a + 6d = 4 \\ \\ a + 6( - 4) = 4 \\ \\ a - 24 = 4 \\ \\ a = 4 + 24 \\ \\ \bf \: a = 28$

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