Question

find the remainder when 7^21+7^22+7^23+7^24 is divided by 25

Answer 1

$\textbf{Given expression is}$

$7^21+7^22+7^23+7^24$

$\text{Taking 7^{21} as common}$

$=7^{21}(1+7^1+7^2+7^3)$

$=7^{21}(1+7+49+343)$

$=7^{21}(400)\;\text{which is divisible by 25}$

$\implies\text{The expression 7^21+7^22+7^23+7^24 is exactly}$

$\text{divisible by 25}$

$\text{Hence the remainder is 0}$

$\therefore\textbf{The remainder when is \bf\,7^21+7^22+7^23+7^24 divided by 25 is 0}$

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find the remainder when 3 x cube minus 6 X square + 3 x minus 7 by 9 is divided by 3 x minus 4

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Answer 2

Answer:

u are correct

Step-by-step explanation:

good answer