I get a number that is too big when I calculate the coefficient of x^25 in:(adsbygoogle = window.adsbygoogle || []).push({});

(2x - (3/x^2))^58

This is how I found the coefficient:

This comes out to be a gigantic number. So I am unsure whether it is anywhere close to being correct despite that I thought that I followed the steps correctly. : \Code (Text):

Note that (58) = A combination value...

k

(58) * (2x)^(58-k) * (-3/x^2)^k

k

(58) * (2)^(58 - k) * (x)^(58 - k) * (-3)^k * (1/x^2)^k

k

(58) * (2)^(58 - k) * (-3)^k * (x)^(58 - k) * (x)^-2k

k

(58) * (2)^(58 - k) * (-3)^k * (x)^(58 - 3k)

k

58 - 3k = 25

-3k = -33

k = 11

So:

(58) * 2^47 * (-3)^11 * (x)^25

11

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# Binomial Theorem

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