Math, asked by rishirajnadan, 1 year ago

solve this question in copy step step

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Answered by Riishika
11
Hello ☺


a21 = a + 20 d

a7 = a +6d

According to the question = a21 - a7 = 84

=> a + 20d - ( a + 6d ) = 84

=> a + 20d - a - 6d = 84

=> 14d = 84

\huge{Answer :  \:\:\:\:  d = 6}

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